Astronomy
gonova - A wrapper for libnova -- Celestial Mechanics, Astrometry and Astrodynamics Library
meeus - Implementation of "Astronomical Algorithms" by Jean Meeus
novas - Interface to the Naval Observatory Vector Astrometry Software (NOVAS)
go-fits - FITS (Flexible Image Transport System) format image and data reader

Build Tools
colorgo - Colorize go build output
fileembed-go - This is a command-line utility to take a number of source files, and embed them into a Go package
gb - A(nother) build tool for go, with an emphasis on multi-package projects
GG - A build tool for Go in Go
go-pkg-config - lightweight clone of pkg-config
goam - A simple project build tool for Go
godag - A frontend to the Go compiler collection
goenv - goenv provides Go version and Go workspace management tools
goscons - Another set of SCons builders for Go
gotgo - An experimental preprocesor to implement 'generics'
goxc - A build tool with a focus on cross-compiling, packaging, versioning and distribution
GVM - GVM provides an interface to manage Go versions
SCons Go Tools - A collection of builders that makes it easy to compile Go projects in SCons

Caching
cache2go - A caching library with expiration capabilities and access counters
go-cache - An in-memory key:value store/cache (similar to Memcached) library for Go, suitable for single-machine applications
gomemcache - a memcached client
gomemcached - A memcached server in go
groupcache - Caching and cache-filling library, intended as a replacement for memcached in many cases
libmemcache - Fast client and server libraries speaking memcache protocol
memcache - go memcached client, forked from YouTube Vitess
memcached - Fast memcache server, which supports persistence and cache sizes exceeding available RAM
memcached-bench - Benchmark tool for memcache servers
YBC bindings - Bindings for YBC library providing API for fast in-process blob cache

Cloud Computing
Docker - The Linux container runtime. Developed by dotCloud.
gocircuit - A distributed operating system that sits on top of the traditional OS on multiple machines in a datacenter deployment. It provides a clean and uniform abstraction for treating an entire hardware cluster as a single, monolithic compute resource. Developed by Tumblr.
gosync - A package for syncing data to and from S3.
juju - Orchestration tool (deployment, configuration and lifecycle management), developed by Canonical.
ShipBuilder - ShipBuilder is a minimalist open source platform as a service, developed by Jay Taylor.
Tsuru - Tsuru is an open source polyglot cloud computing platform as a service (PaaS), developed by Globo.com.
swift - Go language interface to Swift / Openstack Object Storage / Rackspace cloud files

Command-line Option Parsers
argcfg - Use reflection to populate fields in a struct from command line arguments
cobra - A commander for modern go CLI interactions supporting commands & POSIX/GNU flags
command - Add subcommands to your CLI, provides help and usage guide.
getopt - Yet Another getopt Library for Go. This one is like Python's.
getopt - full featured traditional (BSD/POSIX getopt) option parsing in Go style
gnuflag - GNU-compatible flag parsing; substantially compatible with flag.
go-flags - command line option parser for go
go-options - A command line parsing library for Go
goopt - a getopt clone to parse command-line flags
options - Self documenting CLI options parser
opts.go - lightweight POSIX- and GNU- style option parsing
pflag - Drop-in replacement for Go's flag package, implementing POSIX/GNU-style --flags.
subcommands - A concurrent, unit tested, subcommand library
go-commander - Simplify the creation of command line interfaces for Go, with commands and sub-commands, with argument checks and contextual usage help. Forked from the "go" tool code.
uggo - Yet another option parser offering gnu-like option parsing. This one wraps (embeds) flagset. It also offers rudimentary pipe-detection (commands like ls behave differently when being piped to).

Command-line Tools
GoPasswordCreator - A small tool, which creates random passwords
gich - A cross platform which utility written in Go
gocreate - Command line utility that create files from templates.
gojson - Command-line tool for manipulating JSON for use in developing Go code.
jsonpp - A fast command line JSON pretty printer.
passhash - Command-line utility to create secure password hashes
pwdgen - A small tool, which generate human password, written in Go.
tecla - Command-line editing library
DevTodo2 - A small command-line per-project task list manager.

Compression
dgolzo - LZO bindings
fast-archiver - Alternative archiving tool with fast performance for huge numbers of small files
gbacomp - A Go library to (de)compress data compatible with GBA BIOS
go-lz4 - Port of LZ4 lossless compression algorithm to Go.
go-lzss - Implementation of LZSS compression algorithm in Go
go-sevenzip - Package sevenzip implements access to 7-zip archives (wraps C interface of LZMA SDK)
go-zip - A wrapper around C library libzip, providing ability to modify existing ZIP archives.
lzma - compress/lzma package for Go
snappy-go - Google's Snappy compression algorithm in Go
yenc - yenc decoder package
zappy - Package zappy implements the zappy block-based compression format. It aims for a combination of good speed and reasonable compression.

Configuration File Parsers
gcfg - read INI-style configuration files into Go structs; supports user-defined types and subsections
globalconf - Effortlessly persist to and read flag values from an ini config file
goconf - a configuration file parser
toml :
go-toml - Go library for the TOML language
go-toml-config - TOML-based config for Go
toml - TOML parser for Go with reflection
toml-go - An easy-to-use Go parser for the Toml format
gp-config - Subset of TOML syntax with basic and reflection APIs

yaml :
yaml - YAML support for the Go language, by Canonical
goyaml - A port of LibYAML to Go

Console User Interface
ansi - Easily create ansi escape code strings and closures to fomat, color console output
ansiterm - pkg to drive text-only consoles that respond to ANSI escape sequences
gnureadline - GNU Readline bindings
go.linenoise - Linenoise bindings (simple and easy readline with prompt, optional history, optional tab completion)
go-stfl - a thin wrapper around STFL, an ncurses-based widget toolkit
gockel - a Twitter client for text terminals
gocurse - Go bindings for NCurses
gocurses - NCurses wrapper
goncurses - An ncurses library, including the form, menu and panel extensions
gopass - Allows typing of passwords without echoing to screen
igo - A simple interactive Go interpreter built on exp/eval with some readline refinements
oh - A Unix shell written in Go
pty - obtain pseudo-terminal devices
termbox-go - A minimalist alternative to ncurses to build terminal-based user interfaces
termios - Terminal support
termon - Easy terminal-control-interface for Go.
go.sgr - Terminal/console colors and text decoration (bold,underlined,etc).
go-web-shell - Remote web shell, implements a net/http server.

Cryptography
BLAKE2b - Go implementation of BLAKE2b hash function
cryptoPadding - Block padding schemes implemented in Go
dkeyczar - Go port of Google'e Keyczar cryptography library
dkrcrypt - Korean block ciphers: SEED and HIGHT
dskipjack - Go implementation of the SKIPJACK encryption algorithm
go-hc128 - Go implementation of HC-128, an eSTREAM stream cipher
GoSkein - Implementation of Skein hash and Threefisch crypto for Go
keccak - A keccak (SHA-3) implementation
ketama.go - libketama-style consistent hashing
kindi - encryption command line tool
scrypt - Go implementation of Colin Percival's scrypt key derivation function
simpleaes - AES encryption made easy
ssh.go - SSH2 Client library
siphash - SipHash: a fast short-input pseudorandom function
tiger - Tiger cryptographic hashing algorithm
whirlpool - whirlpool cryptographic hashing algorithm
cryptogo - some useful cryptography-related functions, including paddings (PKCS7, X.923), PBE with random salt and IV

Data Processing
Heka - Real time data and log file processing engine.
gostatsd - Statsd server and library.
proto - Map/Reduce/Filter etc. for Go using channels as result streams.
rrd - Bindings for rrdtool.

Data Structures
Lists
GoArrayList - GoArrayList is a Go language substitute for the Java class ArrayList, with very nearly all features.
goskiplist - A skip list implementation in Go.
itreap - An immutable ordered list, interally a treap.
ListDict - Python List and Dict for Go
skip - A fast position-addressable ordered map and multimap.
skiplist - A skip list implementation. Highly customizable and easy to use.
Skiplist - A fast indexable ordered multimap.

Queues
fifo_queue - Simple FIFO queue
go-priority-queue - An easy to use heap implementation with a conventional priority queue interface.
go.fifo - Simple auto-resizing thread-safe fifo queue.
gopqueue - Priority queue at top of container/heap
gringo - A minimalist queue implemented using a stripped-down lock-free ringbuffer
figo - A simple fifo queue with an optional thread-safe version.
queued - A simple network queue daemon

Graphs
goraph - Graph Visualization, Algorithms

Trees
b - Package b implements B+trees with delayed page split/concat and O(1) enumeration. Easy production of source code for B+trees specialized for user defined key and value types is supported by a simple text replace.
btree - Package btree implements B-trees with fixed size keys, http://en.wikipedia.org/wiki/Btree
go-avltree - AVL tree (Adel'son-Vel'skii & Landis) with indexing added
go-darts - Double-ARray Trie System for golang
go-stree - A segment tree implementation for range queries on intervals
GoLLRB - A Left-Leaning Red-Black (LLRB) implementation of 2-3 balanced binary search trees in Google Go
rbtree - Yet another red-black tree implementation, with a C++ STL-like API
rtreego - an R-Tree library
gotree - Tree Visualization, Algorithms

Other
asyncwr - Asynchronous, non-blocking, wrapper for io.Writer
bigendian - binary parsing and printing
collections - Several common data structures
data-structures - A collection of data-structures (AVL Tree, B+Tree, Ternary Search Trie, Hash Table (Separate Chaining), Linear Hash Table)
deepcopy - Make deep copies of data structures
dgobloom - A Bloom Filter implementation
epochdate - Compact dates stored as days since the Unix epoch
fsm - Minimalistic state machine for use instead of booleans
go-algs/ed - Generalized edit-distance implementation
go-algs/maxflow - An energy minization tool using max-flow algorithm.
go-extractor - Go wrapper for GNU libextractor
go-maps - Go maps generalized to interfaces
gohash - A simple linked-list hashtable that implements sets and maps
Gokogiri - A lightweight libxml wrapper library
GoNetCDF - A wrapper for the NetCDF file format library
goop - Dynamic object-oriented programming support for Go
goset - A simple, thread safe Set implementation
gotoc - A protocol buffer compiler written in Go
goxml - A thin wrapper around libxml2
itertools - Provides generic iteratable generator function along with functionality similar to the itertools python package.
jsonv - A JSON validator
libgob - A low level library for generating gobs from other languages
Picugen - A general-purpose hash/checksum digest generator.
ps - Persistent data structures
samling - Package samling implements various collection data structures.
tribool - Ternary (tree-valued) logic for Go
Tuple - Tuple is a go type that will hold mixed types / values
vcard - Reading and writing vcard file in go. Implementation of RFC 2425 (A MIME Content-Type for Directory Information) and RFC 2426 (vCard MIME Directory Profile).
x2j - Unmarshal XML doc into mapstringinterface{} or JSON
xlsx - A library to help with extracting data from Microsoft Office Excel XLSX files.

Databases and Storage
See also SQLDrivers page.
MongoDB
mgo - Rich MongoDB driver for Go

MySQL
Go-MySQL-Driver - A lightweight and fast MySQL-Driver for Go's database/sql package
MyMySQL - MySQL Client API written entirely in Go.
vitess - Scaling MySQL databases for the web

ODBC
go-odbc - ODBC Driver for Go
odbc3-go - This package is wrapper around ODBC (version 3).

PostgreSQL
go-libpq - cgo-based Postgres driver for Go's database/sql package
go-pgsql - A PostgreSQL client library for Go
pgsql.go - PostgreSQL high-level client library wrapper
pgx - Go PostgreSQL driver that avoids database/sql in exchange for better PostgreSQL specific support
pq - Pure Go PostgreSQL driver for database/sql

QL
ql - A pure Go embedded (S)QL database.

Redis
Go-Redis - Client and Connectors for Redis key-value store
godis - Simple client for Redis
Tideland CGL Redis - Powerful Redis client with pub/sub support.
Redigo - Go client for Redis.
redis - Redis client for Golang

RethinkDB
rethinkgo - Basic Go driver for RethinkDB

SQLite
mattn's go-sqlite3 - sqlite3 driver conforming to the built-in database/sql interface
gosqlite - a trivial SQLite binding for Go.
gosqlite (forked) - A fork of gosqlite
gosqlite3 - Go Interface for SQLite3

ORM
beedb - beedb is an ORM for Go. It lets you map Go structs to tables in a database
gorm - An ORM library for Go, aims for developer friendly
gorp - SQL mapper for Go
hood - Database agnostic ORM for Go. Supports Postgres and MySQL.
qbs - Query By Struct. Supports MySQL, PosgreSQL and SQLite3.
xorm - A Simple and Powerful ORM for Go.
go-modeldb - A simple wrapper around sql.DB for struct support.

Multiple wrappers
gosexy/db - an abstraction of wrappers for popular third party SQL and No-SQL database drivers.

Key-Value-Stores
dbm - Package dbm (WIP) implements a simple database engine, a hybrid of a hierarchical and/or a key-value one.
Diskv - Home-grown, disk-backed key-value store
etcd - Highly-available key value store for shared configuration and service discovery
gocask - Key-value store inspired by Riak Bitcask. Can be used as pure go implementation of dbm and other kv-stores.
kv - Yet another key/value persistent store. Atomic operations, two phase commit, automatic crash recovery, ...
leveldb-go - This is an implementation of the LevelDB key/value database.
levigo - levigo provides the ability to create and access LevelDB databases.
persival - Programatic, persistent, pseudo key-value storage

NoSQL
tiedot - A NoSQL document database engine using JSON for documents and queries; it can be embedded into your program, or run a stand-alone server using HTTP for an API.

Other
cabinet - Kyoto Cabinet bindings for go
cass - Cassandra Client Lib
cdb.go - Create and read cdb ("constant database") files
CodeSearch - Index and perform regex searches over large bodies of source code
couch-go - newer maintained CouchDB database binding
couchgo - The most feature complete CouchDB Adapter for Go. Modeled after couch.js.
dbxml - A basic interface to Oracle Berkeley DB XML
go-db-oracle - GO interface to Oracle DB
go-notify - GO bindings for the libnotify
go-rexster-client - Go client for the Rexster graph server (part of the TinkerPop suite of graph DB tools)
go-sphinx - A sphinx client package for Go, for full text search.
go-wikiparse - mediawiki dump parser for working with wikipedia data
gographite - statsd server in go (for feeding data to graphite)
gokabinet - Go bindings for Kyoto Cabinet DBM implementation
goprotodb - A binding to Berkeley DB storing records encoded as Protocol Buffers.
goriak - Database driver for riak database (project homepage is now on bitbucket.org)
goriakpbc - Riak driver using Riak's protobuf interface
gotyrant - A Go wrapper for tokyo tyrant
hdfs - go bindings for libhdfs
JGDB - JGDB stands for Json Git Database
mig - Simple SQL-based database migrations
mongofixtures - A Go quick and dirty utility for cleaning MongoDB collections and loading fixtures into them.
Neo4j-GO - Neo4j REST Client in golang
neoism - Neo4j graph database client, including Cypher and Transactions support.
Optimus Cache Prime - Smart cache preloader for websites with XML sitemaps.
riako - High level utility methods for interacting with Riak databases
Weed File System - fast distributed key-file store
whisper-go - library for working with whisper databases
squirrel - Fluent SQL generation for golang

Development Tools
cwrap - Go wrapper (binding) generator for C libraries.
demand - Download, build, cache and run a Go app easily.
godev - Recompiles and runs your Go code on source change. Also watches all your imports for changes.
GoWatch - GoWatch watches your dev folder for modified files, and if a file changes it restarts the process.
glib - Bindings for GLib type system
gocog - A code generator that can generate code using any language
godiff - diff file comparison tool with colour html output
syntaxhighlighter - language-independent code syntax highlighting library
gonew - A tool to create new Go projects
go-play - A HTML5 web interface for experimenting with Go code. Like http://golang.org/doc/play but runs on your computer
gorun - Enables Go source files to be used as scripts.
go-spew - Implements a deep pretty printer for Go data structures to aid in debugging
goven - Easily copy code from another project into yours
gowatcher - Reload a specified go program automatically by monitoring a directory.
goweb - Literate programming tools for Go based on CWEB by Donald Knuth and Silvio Levy.
hopwatch - simple debugger for Go
hsandbox - Tool for quick exprimentation with Go snippets
Livedev - Livedev is a development proxy server that enables live code reloading.
liccor - A tool for updating license headers in Go source files
liteide - An go auto build tools and qt-based ide for Go
rerun - Rerun watches your binary and all its dependencies so it can rebuild and relaunch when the source changes.
trace - A simple debug tracing
godepgraph - Create a dependency graph for a go package

Emacs Tags
egotags - ETags generator
tago - Emacs TAGS generator for Go source
tago1 - etags generator for go that builds with go 1

Distributed/Grid Computing
donut - A library for building clustered services in Go
locker - A distributed lock service built on top of etcd.
Skynet - Skynet is distributed mesh of processes designed for highly scalable API type service provision.

Documentation
GoDoc.org - GoDoc.org generates documentation on the fly from source on Bitbucket, Github, Google Project Hosting and Launchpad.
Mango - Automatically generate unix man pages from Go sources
godocdown - Format package documentation (godoc) as GitHub friendly Markdown
redoc - Commands documentation for Redis
sphinxcontrib-golangdomain - Sphinx domain for Go

Editors
Go conTEXT - Highlighter plugin for the conTEXT editor
Google Go for Idea - Google Go language plugin for Intellij IDEA
go-gedit - Google Go language plugin for gedit
goclipse - An Eclipse-based IDE for Go.
godev - Web-based IDE for the Go language
gofinder - (code) search tool for acme
golab - go local application builder - a web-based golang ide
tabby - Source code editor
godit - A microemacs-like text editor written in Go.
ViGo - A vim-like text editor.
Conception - Conception is an experimental research project, meant to become a modern IDE/Language package. demo video

Encodings and Character Sets
Mahonia - Character-set conversion library in Go
base58 - Human input-friendly base58 encoding
bencode-go - Encodeing and decoding the bencode format used by the BitTorrent peer-to-peer file sharing protocol
bsonrpc - BSON codec for net/rpc
chardet - Charset detection library ported from ICU
charmap - Character encodings in Go
go-charset - Conversion between character sets. Native Go.
go-simplejson - a Go package to interact with arbitrary JSON
go-xdr - Pure Go implementation of the data representation portion of the External Data Representation (XDR) standard protocol as specified in RFC 4506 (obsoletes RFC 1832 and RFC 1014).
gopack - Bit-packing for Go
gobson - BSON (de)serializer
iconv-go - iconv wrapper with Reader and Writer
mimemagic - Detect mime-types automatically based on file contents with no external dependencies
go-msgpack - Comprehensive MsgPack library for Go, with pack/unpack and net/rpc codec support (DEPRECATED in favor of codec )
codec-msgpack-binc High Performance and Feature-Rich Idiomatic Go Library providing encode/decode support for multiple binary serialization formats: msgpack and binc.
msgpack - Msgpack format implementation for Golang
msgpack-json - Command-line utilities to convert between msgpack and json
storable - Write perl storable data
TNetstring - tnetstrings (tagged Netstrings)
nnz - String and Int primitives that serialize to JSON and SQL null
magicmime -- Mime-type detection with Go bindings for libmagic

Games
bloxorz - Solver for bloxorz basic levels
ChessBuddy - Play chess with Go, HTML5, WebSockets and random strangers!
Fergulator - An NES emulator, using SDL and OpenGL
Gongo - A program written in Go that plays Go
Ludo Game - Ludo Board game powered by Go on Appengine
godoku - Go Sudoku Solver - example of "share by communicating"
gospeccy - A ZX Spectrum 48k Emulator
Bampf - Arcade style game based on the Vu 3D engine.

GIS
go-gdal - Go bindings for GDAL
go-liblas - Go bindings for libLAS
go-proj-4 - An interface to the Cartographic Projections Library PROJ.4
gogeos - Go library for spatial data operations and geometric algorithms
lvd.go - dense set, byte trie, reed solomon encoding, wgs84 geodesics
polyline - Google Maps polyline encoding and decoding
geom - Open Geo Consortium-style geometries with native Go GeoJSON, WKB, and WKT encoding and decoding (work-in-progress)

Go Implementations
Express Go - Interpreted Go implementation for Windows
llgo - LLVM-based Go compiler, written in Go (work-in-progress)

Graphics and Audio
AnsiGo - Simple ANSi to PNG converter written in pure Go
Arclight - Arclight is a tool for rendering images
Go-OpenGL - Go bindings for OpenGL
GoGL - OpenGL binding generator
GoMacDraw - A mac implementation of go.wde
Goop - Audio synthesizer engine
Plotinum - An API for creating plots
Winhello - An example Windows GUI hello world application
allergro - basic wrapper for the Allegro library
allegro 5 - Go Bindings for Allegro 5 library
baukasten - A modular game library.
blend - Image processing library and rendering toolkit for Go.
bmp.go - package for encoding/decoding Windows BMP files
chart - Library to generate common chart (pie, bar, strip, scatter, hstogram) in different output formats.
draw2d - This package provide an API to draw 2d geometrical form on images. This library is largely inspired by postscript, cairo, HTML5 canvas.
freetype-go - a Go implementation of FreeType
gl - OpenGL bindings using glew
glfw - bindings to the multi-platform library for opening a window, creating an OpenGL context and managing input
glfw 3 - Go bindings for GLFW 3 library
glh - OpenGL helper functions to manage text, textures, framebuffers and more
glu - bindings to the OpenGL Utility Library
egl - egl bindings
es2 - es2 bindings
go-cairo - Go wrapper for the cairo graphics library
go-gd - Go bingings for GD
go-gnuplot - go bindings for GNUPlot
go-gtk3 - gtk3 bindings for go
go-heatmap - A toolkit for making heatmaps
go-openal - Experimental OpenAL bindings for Go
go-opencl - A go wrapper to the OpenCL heterogeneous parallel programming library
gocl - Go OpenCL (gocl) binding
go-opencv - Go bindings for OpenCV
go-taglib - Go wrapper for TagLib, an audio meta-data parser
go-tmx - A Go library that reads Tiled's TMX files
go-vlc - Go bindings for libVLC
go.wde - A windowing/drawing/event interface
GoHM - H.265/HEVC HM Video Codec in Go
GoVisa - H265/HEVC Bitstream Analyzer in Go
goHorde - Go Bindings for the Horde3d Rendering engine.
gocairo - Golang wrapper for cairo graphics library
goexif - Retrieve EXIF metadata from image files
goray - Raytracer written in Go, based on Yafaray
gosc - Pure Go OSC (Open Sound Control) library
gosdl - Go wrapper for SDL
goxscr - Go rewrites of xscreensaver ports
gst - Go bindings for GStreamer
hgui - Gui toolkit based on http and gtk-webkit.
imaging - Package imaging provides basic image manipulation functions (resize, rotate, flip, crop, etc.) as well as simplified image loading and saving.
portaudio - A Go binding to PortAudio
pulsego - Go binding for PulseAudio
resize - Image resizing with different interpolations.
starfish - A simple Go graphics and user input library, built on SDL
svgo - a library for creating and outputting SVG
tga - TARGA image format encoding/decoding library
window - Optimized moving window for real-time data
wingo - A fully-featured window manager written in Go.
wxGo - Go Wrapper for the wxWidgets GUI
x-go-binding - bindings for the X windowing system
xgb - A fork of the x-go-binding featuring support for thread safety and all X extensions.
xgbutil - A utility library to make use of the X Go Binding easier. (Implements EWMH and ICCCM specs, key binding support, etc.)
vu - Virtual Universe. A skeleton 3D engine.

GUIs and Widget Toolkits
go-fltk - FLTK2 GUI toolkit bindings for Go
go-gtk - Bindings for GTK
go-qt5 - qt5 bindings for go
go.uik - A UI kit for Go, in Go. (project is closed)
GoQuick - Go and Qt Quick experimentation
gothic - Tcl/Tk Go bindings
gotk3 - Go bindings for GTK3, requires GTK version 3.8
go-webkit2 - Go bindings for the WebKitGTK+ v2 API (w/headless browser & JavaScript support)
Gowut - Gowut (Go Web UI Toolkit) is a full-featured, easy to use, platform independent Web UI Toolkit written in pure Go, no platform dependent native code is linked or called.
iup - Bindings for IUP
mdtwm - Tiling window manager for X
qml - QML support for the Go language

Hardware
go.hid - Provides communication with USB Human Interface Devices.
hwio - Hardware I/O library for SoC boards including BeagleBone Black and Raspberry Pi.
gortlsdr - A librtlsdr wrapper, which turns certain USB DVB-T dongles into a low-cost, general purpose software-defined radio receiver.

Language and Linguistics
alpinocorpus-go - A reader and a writer for Alpino corpora.
go-aspell - GNU Aspell spell checking library bindings for Go.
go-language - A simple language detector using letter frequency data.
go.stringmetrics - String distance metrics implemented in Go
inflect - Word inflection library (similar to Ruby ActiveSupport::Inflector). Singularize(), Pluralize(), Underscore() etc.
libtextcat - A Go wrapper for libtextcat.
textcat - N-gram based text categorization, with support for utf-8 and raw text
sego - Chinese language segmenter.
goling - String Similarity(Cosine Similarity, Levenshtein Distance), Spell Check, Segmentation
gobay - Naive Bayesian Classifier (Sentiment Analysis)
gocha - CHILDES data analyzing tool
gomata - Automata Theory, Computational Linguistics

Logging
glog - Leveled execution logs for Go
factorlog - Really fast, featureful logging infrastructure (supports colors, verbosity, and many formats)
seelog - Flexible dispatching, filtering, and formatting
timber - Configurable Logger for Go
log4go - Go logging package akin to log4j
syslog - With this package you can create your own syslog server with your own handlers for different kind of syslog messages
graylog-golang - graylog-golang is a full implementation for sending messages in GELF (Graylog Extended Log Format) from Google Go (Golang) to Graylog
rfw - Rotating file writer - a 'logrotate'-aware file output for use with loggers

Machine Learning
bayesian - A naive bayes classifier.
go-galib - Genetic algorithms.
go-porterstemmer - An efficient native Go clean room implementation of the Porter Stemming algorithm.
paicehusk - Go implementation of the Paice/Husk Stemmer
snowball - Snowball stemmer

Mathematics
Cvx - Convex optimization package, port of CVXOPT python package
Units - Implements types, units, converter functions and some mathematics for some common physical types. lib
bayesian - Naive Bayesian Classification for Golang
blas - Go implementation of BLAS (Basic Linear Algebra Subprograms)
cartconvert - cartography functions for the Go programming language
dice - Dice rolling library
evaler - A simple floating point arithmetic expression evaluator
fixed - A fixed point (Q32.32 format) math library.
geom - 2d geometry.
go.mahalanobis - Naive implementation of the Mahalanobis distance using go.matrix
go-fftw - Go bindings for FFTW - The Fastest Fourier Transform in the West
go-fn - Special functions that would not fit in "math" pkg
go-gt - Graph theory algorithms
go-humanize - Formatting numbers for humans.
go-lm - Linear models in Go. Provides WLS and regression with t residuals via a cgo -> BLAS/LAPACK interface.
go-symexpr - Symbolic math as an AST with derivatives, simplification, and non-linear regression
go.matrix - a linear algebra package
gochipmunk - Go bindings to the Chipmunk Physics library.
gocomplex - a complex number library
godec - multi-precision decimal arithmetic
gographviz - Graphviz DOT language parser for golang
gomat - lightweight FAST matrix and vector math
gsl - GNU Scientific Library bindings
mathutil - Package mathutil provides utilities supplementing the standard 'math' and 'rand' packages.
mt19937_64 - Mersenne Twister int64 random source
polyclip.go - Go implementation of algorithm for Boolean operations on 2D polygons
pso-go - A library of PSO (Particle Swarm Optimization) for golang.
statistics - GNU GSL Statistics (GPLv3)
vector - A small vector lib.

Misc
GCSE - Go code search engine. source
CGRates - Rating system designed to be used in telecom carriers world
Go-PhysicsFS - Go bindings for the PhysicsFS archive-access abstraction library.
go.pipeline - Library that emulates Unix pipelines
GoFlow - Flow-based and dataflow programming library for Go
GoLCS - Sovle Longest Common Sequence problem in go
Gotgo - A Go preprocessor that provides an implementation of generics
Hranoprovod - Command-line calorie tracking
Tideland CGL Monitoring - Flexible monitoring of your application
atexit - Simple atexit library
bíogo - Basic bioinformatics functions for the Go language.
cpu - A Go package that reports processor topology
cron - A library for running jobs (funcs) on a cron-formatted schedule
dbus-go - D-Bus Go library
desktop - Open file/uri with default application (cross platform)
devboard - Kanban board application based on Simple-Khanban
dump - An utility that dumps Go variables, similar to PHP's var_dump
env - Easily pull environment variables with defaults
epub - Bindings for libepub to read epub content.
faker - Generate fake data, names, text, addresses, etca
fsnotify - File system notifications for Go
functional - Functional programming library including a lazy list implementation and some of the most usual functions.
go-amiando - Wrapper for the Amiando event management API
go-bit - An efficient and comprehensive bitset implementation with utility bit functions.
go-business-creditcard - Validate/generate credit card checksums/names.
gochem - A computational chemistry/biochemistry library.
go-ean - A minimal utility library for validating EAN-8 and EAN-13 and calculating checksums.
go-eco - Functions for use in ecology
go-erx - Extended error reporting library
go-fann - Go bindings for FANN, library for artificial neural networks
go-idn - a project to bring IDN support to Go, feature compatible with libidn
go-metrics - Go port of Coda Hale's Metrics library
go-osx-plist - CoreFoundation Property List support for Go
go-papi - Go interface to the PAPI performance API
go-pkg-mpd - A library to access the MPD music daemon
go-pkg-xmlx - Extension to the standard Go XML package. Maintains a node tree that allows forward/backwards browser and exposes some simpel single/multi-node search functions
go-qrand - Go client for quantum random bit generator service at random.irb.hr
go-semvar - Semantic versions (see http:/semver.org)
go-taskstats - Go interface for Linux taskstats
go-translate - Google Language Translate library
go-uuid - Universal Unique IDentifier generator and parser
go.dbus - Native Go library for D-Bus
go.pcsclite - Go wrapper for pcsc-lite
goNI488 - A Go wrapper around National Instruments NI488.2 General Purpose Interface Bus (GPIB) driver.
goPromise - Scheme-like delayed evaluation for Go
goST - A steam properties (steam table) library written for Go. This was designed as a native go equivalent to XSteam.
gocsv - Library for CSV parsing and emitting
goga - A genetic algorithm framework
gogobject - GObject-introspection based bindings generator
golife - Implementation of Game of Life for command line
gomagic - Libmagic bindings
go-magic - A Go wrapper for libmagic
go-magic - Simple interface to libmagic for Go Programming Language
gommap - gommap enables Go programs to directly work with memory mapped files and devices in a very efficient way
goneuro - Go driver for NeuroSky devices.
goplan9 - libraries for interacting with Plan 9
goraphing - A tool to generate a simple graph data structures from JSON data files
go-ses - Amazon AWS Simple Email Service (SES) API client
go-systemd - Utility functions for interacting with the systemd init system
twitterfetcher - A tool to make Twitter API requests using the Application-only authentication
gouuid - Pure Go UUID v3, 4 and 5 generator compatible with RFC4122
Prometheus Instrumentation/Metrics Client - This is a whitebox instrumentation framework for servers written in Go. It exposes programmatically-generated metrics automatically for use in the Prometheus time series collection and post-processing environment.
koans - programming koans for go
lineup - A minimalistic message queue server
mimemail - Construct plain text MIME messages for use with net/smtp.
mitigation - Package mitigation provides the possibility to prevent damage caused by bugs or exploits.
nma.go - A NotifyMyAndroid client for go.
passwd - A parser for the /etc/passwd file
pool - A generic worker pool
primegen.go - Sieve of Atkin prime number generator
procfile - A Procfile parser
randat - Devel tool for generating random bytestrings and encoding files in code-friendly forms
replaykit - A library for replaying time series data.
selenium - Selenium client
go-selenium - Selenium WebDriver client for Go
serial - Serial ports API (pure Go)
sio - Package sio lets you access old serial junk. It's a go-gettable fork and modification of dustin's rs232 package.
symutils - Various tools and libraries to handle symbolic links
udis86 - Go bindings for libudis86
xplor - Files tree browser for p9p acme
yubigo - Yubikey OTP validation and auhtentication API client.
go-villa - Some miscellaneous wrapper and small algorithms.(wrappers to slices, priority queues, path related apis, a string set type)
go.bitcoin - Wrapper for bitcoind daemon API, makes working with bitcoins easy.
Breaker - Breaker enables graceful degraded mode operations by means of wrapping unreliable interservice interface points with circuit breaker primitives.
Wukong - A highly extensible full-text search engine written in Go.
gotenv - Loads environment variables from .env
file

Music
go-libshout - Go bindings for libshout
gompd - A client interface for the MPD (Music Player Daemon)
portmidi - Go bindings for libportmidi
launchpad - A Go client for Novation Launchpad

Networking
Go Ajax - Go Ajax is a JSON-RPC implementation designed to create AJAX powered websites.
GoRTP - RTP / RTCP stack implementation for Go
QRP - QRP is a simple packet-based RPC protocol designed as a simple alternative to Go's rpc, that can run over UDP
Rsync - Rsync algorithm as a Go library
Tonika - Secure social networking platform
Uniqush - A free and open source software which provides a unified push service for server-side notification to apps on mobile devices.
createsend-go - API client for Monitor http://www.campaignmonitor.com (email campaign service)
VDED - Vector Delta Engine Daemon - track deltas in ever-increasing values (written in Go)
circle - Go interface to the libcircle distributed-queue API
dmrgo - Library for with Hadoop Streaming map/reduce
doozerconfig - Go package for managing json-encoded configuration in Doozer
doozerd - A consistent distributed data store
eventsource - Server-sent events for net/http server.
gearman-go - A native implementation for Gearman API with Go.
glibvnc - Go wrapper using CGO for the libvnc library.
gmail - Simple library for sending emails from a Gmail account, for people not interested in dealing with protocol details.
go-curl - libcurl bingding that supports go func callbacks
go-dbus - A library to connect to the D-bus messaging system
go-icap - ICAP (Internet Content Adaptation Protocol) server library
go-imap - IMAP client library
go-mail - Email utilities including RFC822 messages and Google Mail defaults.
nagiosplugin - package for writing Nagios/monitoring plugins
go-nntp - An NNTP client and server library for go
go-router - implementation of remote channel communication
go-rpcgen - ProtoBuf RPC binding generator for net/rpc and AppEngine
go-socket.io - A Socket.IO backend implementation written in Go
gosocks - A SOCKS (SOCKS4, SOCKS4A and SOCKS5) proxy client library in Go.
go9 - an implementation of the 9P distributed file system protocol
go9p - 9p protocol implementation in Go
goagain - zero-downtime restarts in Go
gobeanstalk - Go Beanstalkd client library
godwulf - Gopher server written in Go
gogammu - Library for sending and receiving SMS
gonetbench - Simple TCP benchmarking tool
gonetcheck - package for checking general internet access
gopacket - Packet encoding/decoding, pcap/pfring/afpacket support, TCP assembly, and more!
gopcap - A simple wrapper around libpcap
goprotobuf - the Go implementation of Google's Protocol Buffers
gogoprotobuf - another Go implementation of Protocol Buffers, but with extensions and code generation plugins.
golang_protobuf_extensions - Protocol Buffer extensions to support streaming message encoding and decoding.
goq - A persistent message queue written in Go.
gosndfile - Go binding for libsndfile
gozmq - Go Bindings for 0mq (zeromq/zmq)
handlersocket-go - Go native library to connect to HandlerSocket interface of InnoDB tables
imap - Implementation of IMAP4rev1 client, as described in RFC 3501.
Inbucket - Inbucket is an email testing service; it will accept messages for any email address and make them available to view via a web interface.
ipaddr - basic functions for the manipulation of IP address prefixes and subsequent addresses as described in RFC 4632 and RFC 4291.
ipaddress - Convenient ip address functions: ip -> int, int -> ip, and IPNet broadcast address
iris - Peer-to-peer messaging for back-end decentralization.
iris-go - Go binding for the Iris decentralized messaging framework.
kafka.go - Producer & Consumer for the Kafka messaging system
ldap - Basic LDAP v3 functionality for the GO programming language.
NATS - NATS distributed messaging system client for Go
netsnail - A low-bandwidth simulator
npipe - a pure Go wrapper for Windows named pipes
netutils - Simple interface for turning TCP Sockets into channels.
opendap - Go wrapper for Openldap
protorpc - Google Protocol RPC for Go and C++
remotize - A remotize package and command that helps remotizing methods without having to chaneg their signatures for rpc
replican-sync - An rsync algorithm implementation in Go
rs232 - Serial interface for those of us who still have modems (or arduinos)
rss - RSS parsing library.
seamless - Reverse TCP Proxy with HTTP managment API
spdy - SPDY library, wired into net/http, currently supporting servers only.
statsd-go - Statsd implementation in Go, forked from gographite, which submits to Ganglia
stompngo - A Stomp 1.1 Compliant Client
stompngo_examples - Examples for stompngo.
telnet - A simple interface for interacting with Telnet connection
tcp_fallback - A TCP proxy implementing a simple fallback mechanism.
tcpmeter - A TCP throughput measuring tool
traceroute - A traceoute implementation
uritemplates - A level 4 implementation of URI Templates (RFC 6570)
sockjs-go - Implements server side counterpart for the SockJS-client browser library.
zmq2 - A Go interface to ZeroMQ (zmq, 0MQ) version 2.
zmq3 - A Go interface to ZeroMQ (zmq, 0MQ) version 3.
zmq4 - A Go interface to ZeroMQ (zmq, 0MQ) version 4.
Grumble - Mumble (VoIP) server implementation
go-sslterminator - SSL terminator proxy
gobench - HTTP/HTTPS load test and benchmark tool
Gorilla WebSocket - WebSocket protocol implementation
apiproxy - proxy for HTTP/REST APIs with configurable cache timeouts
httpfstream - streaming append and follow of HTTP resources (using WebSockets)
goproxy - a programmable HTTP proxy.
zero-downtime-daemon - Configurable zero downtime daemon (Hot Update) framework for any kind of TCP,HTTP,FCGI services
boom - HTTP(s) benchmarking tool, Apache Benchmark replacement

DNS
dns - A DNS library in Go
dyndnscd - a configurable dyndns client
GeoDNS - geo-aware authoritative DNS server
grong - Small authoritative DNS name server
mdns - Multicast DNS library for Go
https://github.com/nictuku/bitz - BitMessage client node and library

FTP
ftp - Package ftp provides a minimal FTP client as defined in RFC 959
ftp4go - An FTP client for Go, started as a port of the standard Python FTP client library
goftp - A FTP client library

Instant Messaging
GoTY - "Go Troll Yourself", minimalist client IRC library
go-irc - Simple IRC client library
go-xmpp - XMPP client library
gobir - Extensible IRC bot with channel administration, seen support, and go documentation querying
goexmpp - XMPP client implementation
goirc - event-based stateful IRC client framework
gorobot - a modular IRC bot
irc.go - Go IRC bot framework
ircflu - IRC bot with support for commands, scripting and web-hooks

Operating System Interfaces
Go-fuse - Library to write FUSE filesystems in Go
Go FUSE file system library - From-scratch implementation of the kernel-userspace communication protocol based on Russ Cox'.
https://bitbucket.org/kardianos/service/overview - Service will install / un-install, start / stop, and run a program as a service (daemon) on Windows/Linux and OSX.

Other Random Toys, Experiments and Example Code
go-crazy - An experimental source-to-source compiler for go
go-gtk-demo - A demonstration of how to use GTK+ with Go.
go-hashmap - A hash table in pure go as an experiment in Go performance
goconc - A collection of useful concurrency idioms and functions for Go, compiled
goplay - A bunch of random small programs in Go
lifegame-on-golang - Game of Life in Go
linear - Playing around with the linear algebra
project euler in go - Solutions to Project Euler in Go also
shadergo - shader test using golang
travisci-golang-example - Travis-CI example for Go
gosequence - Slice, Map tricks, Stack, Queue
goroup - Set Theory

P2P and File Sharing
Taipei-Torrent - A BitTorrent client
ed2kcrawler - eDonkey2000 link crawler
gobit - Bittorrent Client in Go
gop2p - A simple p2p app to learn Go
wgo - A simple BitTorrent client based in part on the Taipei-Torrent and gobit code
DHT - Kademlia DHT node used by Taipei-Torrent, compatible with BitTorrent

Programming
go-clang - cgo bindings to the C-API of libclang
go-galib - a library of Genetic Algorithms
go-intset - a library to work with bounded sets of integers, including multiple alternative implementations
go-parse - a Parsec-like parsing library
godeferred - port of jsdeferred: http://cho45.stfuawsc.com/jsdeferred/
gosets - implementation of set types
Shuffle - Implementation of the Fisher–Yates shuffle (or Knuth shuffle) in Go.

Scanner and Parser Generators
ebnf2y - Utility for converting EBNF grammars into yacc compatible skeleton .y files.
fsm - FSM (NFA, DFA) utilities.
golex - Lex/flex like fast (DFA) scanners generator.
gocc - Go Compiler Compiler
gopp - Go Parser Parser
Ragel - State Machine Compiler

Simulation Modeling
godes - Library for building discrete event simulation models

Sorting
funnelsort - Lazy funnel sort -- a cache-oblivious sorting algorithm
Sortutil - Nested, case-insensitive, and reverse sorting for Go.
sortutil - Utilities supplemental to the Go standard "sort" package
tarjan - Graph loop detection function based on Tarjan's algorithm
timsort - Fast, stable sort, uses external comparator or sort.Interface

Source Code Management
go-deps - Analyzes and recursively installs Go package deps (library functionality similar to go get
)
go-pkgs - Finds all matching packages in all of the GOPATH trees (library functionality similar to go list all
)
hggofmt - A Mercurial/hg extension with a hook to
nut - Nut is a tool to manage versioned Go source code packages, called "nuts".
vcstool - VCS abstraction tool
go-diff - A diff command for go languange showing sematic differences of two go source files.
go-vcs - clone and check out revs of VCS repositories (git and hg support)
go-vcsurl Lenient VCS repository URL parsing library

Strings and Text
Black Friday - A markdown processor
NTemplate - Nested Templates
binarydist - Binary diff and patch
columnize - format slice or array into aligned columns
csvutil - A heavy duty CSV reading and writing library.
dgohash - Collection of string hashing functions, including Murmur3 and others
gettext - Feature complete, cgo
gettext-go - GNU's gettext support, written in pure Go
go-guess - Go wrapper for libguess
go-migemo - migemo extension for go (Japanese incremental text search)
goini - A go library to parse INI files.
golorem - lorem ipsum generator
gosphinx - A Go client interface to the Sphinx standalone full-text search engine
gpKMP - String-matching in Golang using the Knuth–Morris–Pratt algorithm
hangul - Handy tools to manipulate korean character.
kasia.go - Templating system for HTML and other text documents
kview - Simple wrapper for kasia.go templates. It helps to modularize content of a website
mail.go - Parse email messages
peg - Parsing Expression Grammer Parser
polyglot - String translation utilities for Go
pretty.go - Pretty-printing for go values
rubex - A simple regular expression library that supports Ruby's regex syntax. It is faster than Regexp.
scanner - A text scanner that parses primitive types, analogous to Java's
segment - An implementation of Norvig's recursive word segmentation algorithm
strogonoff - Stenography with Go
strutil - Package strutil collects utils supplemental to the standard strings package.
text - Text paragraph wrapping and formatting
go-colortext - Change the color of the text and background in the console, working both in Windows and other systems.
goskirt - Upskirt markdown library bindings for Go

Testing
downtest - Automatically run tests for all known downstream consumers of a Go package.
go2xunit - Convert "go test -v" output to xunit XML output
go.assert - helper functions for the built-in 'testing' package (deleted)
goautotest - Automatically run unit tests when code changes are made
GoConvey - Browser-based reporting, uses go test
, supports traditional Go tests, clean DSL
gocov - Code coverage testing/analysis tool
ginkgo - BDD Testing Framework for Go.
Gocheck - Rich test framework with suites, fixtures, assertions, good error reporting, etc
gomega - Ginkgo's Preferred Matcher Library.
gomock - a mocking framework for Go.
GoSpec - a BDD framework
gospecify - another BDD framework
go-stat - performant instrumentation/profiling for Go
go-tap - TAP (Test Anything Protocol) parser in Go
GSpec - Concurrent, minimal, extensible and reliable framework that makes it easy to organize and verify the mind model of software.
Nitro - A quick and simple profiler For Golang
testflight - Painless http testing in Go
terst - A terse, easy-to-use testing library for Go
Testify - A set of packages that provide many tools for testifying that your code will behave as you intend.
Tideland CGL Asserts - Make asserts during testing and inside of your applications

Virtual Machines and Languages
Gelo - Extensible, embeddable interpreter
GoForth - A simple Forth parser
GoLightly - A flexible and lightweight virtual machine with runtime-configurable instruction set
Golog - Prolog interpreter in Go
Minima - A language implemented in Go.
RubyGoLightly - An experimental port of TinyRb to Go
The erGo™ Compiler - An independent implementation of the Go language.
forego - Forth virtual machine
go-python - go bindings for CPython C-API
GoEmPHP - This package is built for Embedding PHP into Golang.
goenv - Create an isolated environment where you install Go packages, binaries, or even C libraries. Very similar to virtualenv for Python.
golemon - A port of the Lemon parser-generator
goll1e - An LL(1) parser generator for the Go programming language.
golua - Go wrapper for LUA's C API
golua-fork - A fork of GoLua that works on current releases of Go
gotcl - Tcl interpreter in Go
meme - Scheme interpreter in Go
ngaro - A ngaro virtual machine to run retroForth images
otto - A JavaScript parser and interpreter written natively in Go
monkey - Embed SpiderMonkey, the Mozilla JavaScript engine, in your Go program.
go-v8 - V8 JavaScript engine bindings for Go
gomruby - mruby (mini Ruby) bindings for Go

Web Applications
Digestw - A Web Application - Twitter's Timeline Digest
GoURLShortener - A frontend for the http://is.gd/ URL shortener
Hugo - A fast and flexible static site generator implemented in Go
Já Vai Tarde - Unfollows monitoring for Twitter
fourohfourfound - A fallback HTTP server that may redirect requests with runtime configurable redirections
goals-calendar - A web-based Seinfeld calendar implemented in Go
goblog - A static blog engine
gocrawl - A polite, slim and concurrent web crawler.
goflash - Flash player implementation in Go language
gogallery - simple web server with an emphasis on easily browsing images
goof - A simple http server to exchange files over http (upload/download)
gopages - A php-like web framework that allows embedding Go code in web pages
kurz.go - a url shortener based on web.go and redis
Monsti - Resource friendly flat file CMS for private and small business sites.
now.go - A simple HTTP-based to-do queue.
sf_server - a tiny send file server and client
webtf - Web app to graphical visualization of twitter timelines using the HTML5
rabbitmq-http - REST API for RabbitMQ

Web Libraries
Authentication
GOAuth - OAuth Consumer
goauth - A library for header-based OAuth over HTTP or HTTPS.
Go-OAuth - OAuth 1.0 client
OAuth Consumer - OAuth 1.0 consumer implementation
authcookie - Package authcookie implements creation and verification of signed authentication cookies.
totp - Time-Based One-Time Password Algorithm, specified in RFC 6238, works with Google Authenticator
dgoogauth - Go port of Google's Authenticator library for one-time passwords
go-http-auth - HTTP Basic and HTTP Digest authentication
httpauth - HTTP session (cookie) based authentication and authorization
httpauth-go - Package httpauth provides utilities to support HTTP authentication policies. Support for both the basic authentication scheme and the digest authentication scheme are provided.
oauth1a - OAuth 1.0 client library

DOM handling
Cascadia - CSS selector library
GoQuery - jQuery-like DOM manipulation library, using Go's experimental HTML package.
html-query - A fluent and functional approach to querying HTML.
HTML Transform - A CSS selector based html scraping and transformation library

Frameworks and Toolkits
Martini - Martini is a popular, lightweight, extensible package for writing modular web apps/services in Go
Beego - Beego is an open source version of the scalable, non-blocking web framework.
Go-Blog - Blog framework written in Go
Golanger - Golanger Web Framework is a lightweight framework for writing web applications in Go.
fcgi_client - Go fastcgi client with fcgi params support
Goldorak.Go - a web miniframework built using mustache.go, web.go and Go-Redis
Gongo Web - Web framework with separate data modeling, control and visualization
GoRest - An extensive configuration(tags) based RESTful style web-services framework.
HttpRouter - A high performance HTTP request router that scales well
Revel - High productivity web framework modeled on Play! Framework
Tideland CGL Web - Package for RESTful web applications
app.go - Web framework for google app engine
browserspeak - Generate HTML templates, CSS or SVG without writing < or >
falcore - Modular HTTP server framework
go-fastweb - aims to be a simple, small and clean MVC framework for go
go-rest - A small and evil REST framework for Go
go-restful - lean package for building REST-style Web Services
go-start - A high level web-framework for Go
go-urlshortener - interface to google's urlshorten API
go-webproject - Modular web application framework and app server
goku - a Web Mvc Framework for golang, mostly like ASP.NET MVC.
golanger - Golanger Web Framework is a lightweight framework for writing web applications in Go
gorilla - Gorilla web toolkit
goweb - Lightweight RESTful web framework for Go providing Ruby on Rails style routing
Gowut - Go Web UI Toolkit is a full-featured, easy to use, platform independent Web UI Toolkit written in pure Go.
mango - Mango is a modular web-application framework for Go, inspired by Rack, and PEP333.
restclient - Client library for interacting with RESTful APIs.
sawsij - Provides a small, opinionated web framework.
trinity - MVC framework
Tiger Tonic - framework for building JSON web services inspired by Dropwizard
web.go - a simple framework to write webapps
wfdr - Simple web framework designed for and written in go. Works with other lanauges as well, but not as well.
GEP - A simple web framework similar to JSP. Writing dynamic pages knowing only Go and HTML(or Markdown)
xweb - A web framework for Go. Just like Struts for Java.
forgery - A clone of the superb Node.js web framework Express.

HTML forms
gforms - HTML forms for Golang
GoForms - Form data validation, cleaning and error reporting - a la django.forms
htmlfiller - Fills in html forms with default values and errors a la Ian Bicking's htmlfill for Python
MonstiForm - HTML form generator and validator library
xsrftoken - A package for generating and validating tokens used in preventing XSRF attacks
revel-csrf - Cross-Site Request Forgery (CSRF) attacks prevention for the Revel framework

Public API Wrappers
adn - Interface to the App.net API
anaconda - Client library for the Twitter 1.1 API
clouddns.go - Go library for the Rackspace Cloud DNS API
ddg - DuckDuckGo API interface
gobo - Client library for Sina Weibo.
gocaptcha - gocaptcha provides easy access to the reCaptcha API in go.
go-dealmap - Go library for accessing TheDealMap's API
go-dropbox - API library for dropbox
facebook - Up-to-date facebook graph API client. Handy and flexible.
go-facebook - Go implementations of facebook APIs.
go-flickr - A wrapper for Flickr's API
go-gravatar - Wrapper for the Gravatar API
go-libGeoIP - GO Lib GeoIP API for Maxmind
gomojo - Instamojo API wrapper
gomwapi - Access mediawiki contents like wikipedia, wiktionary in golang
googtrans - unofficial go bindings for Google Translate API v2
go-recaptcha - Handles reCaptcha form submissions in Go
gorecurly - A Client app to use with Recurly's api
go.stripe - a simple credit card processing library for Go using the Stripe API
Gotank - Searchify's Go client for the IndexTank full-text search API
go-tripit - Go API library for the TripIt web services
GoTwilio - Twilio library for Go (golang). Very basic at the moment.
gravatar - Gravatar image/profile API library
justintv - Justin.tv REST API with oauth
postmark - Access postmark API from Go
reddit.go - Client library for Reddit API
shorturl - Generic implementation for interacting with various URL shortening services.
Stack on Go - Go wrapper for Stack Exchange API
twilio - Simple Twilio API wrapper
twittergo - Client library for Twitter's API

Other
adhoc-http - Quick & dirty HTTP static file server
assets - Helps prepares CSS and JS files for development and production of Go web apps.
bwl - a set of libraries to help build web sites
captcha - Image and audio captcha generator and server
gaerecords - Lightweight wrapper around appengine/datastore providing Active Record and DBO style management of data
get2ch-go - a library to access the 2channel Japanese web bulletin board
go-gzip-file-server - A net.http.Handler similar to FileServer that serves gzipped content
go-httpclient - a Go HTTP client with timeouts
go-pkg-rss - a packages that reads RSS and Atom feeds
go-rss - Simple RSS parser, tested with Wordpress feeds.
go-twitter - another Twitter client
go-twitter-oauth - a simple Twitter client (supports OAuth)
gohaml - An implementation of the popular XHTML Abstraction Markup Language using the Go language.
gojwt - Json Web Tokens for Go
goreman - foreman clone
goroute - A very simple URL router based on named submatches of regular expression that works well with http.Handler .
gorouter - Simple router for go to process url variables
goscribble - An MPD Audioscrobble
GoSrv - A Go HTTP server that provides simple command line functionality, config loading, request logging, graceful connection shutdown, and daemonization.
grender - Go static site generator
halgo - HAL-compliant API client and serialisation library.
http-gonsole - Speak HTTP like a local. (the simple, intuitive HTTP console, golang version)
httprpc - HTTP RPC codecs (json2, soap, rest)
HypeCMS - A flexible CMS built with Go and MongoDb.
Kontl - A client for kon.tl's URL shortening service
mustache.go - an implementation of the Mustache template language
muxer - Simple muxer for a Go app without regexp
Optimus Sitemap Generator - A universal XML sitemap generator
passwordreset - Creation and verification of secure tokens useful for implementation of "reset forgotten password" feature in web applications.
pat - A Sinatra style pattern muxer
persona - remote verification API for persona
plex - simple, small, light, regexp http muxer with chaining
purell - tiny Go library to normalize URLs
pusher.go - HTTP Server Push module for the standard http package
rest.go (forked) - forked rest.go for improvements and REST consistency
rest2go - Based on rest.go, forked for improvements and REST consistency
robotstxt - The robots.txt exclusion protocol implementation. Allows to parse and query robots.txt file.
RSS-Go - RSS and ATOM feed reader package for the Go programming language.
seshcookie - A web session library inspired by Beaker
user_agent - An HTTP User-Agent parser
webdriver - WebDriver (Selenium) client
webtestutil - Web and HTTP functional testing utilities. Includes Gorilla testing support.
gorefit - A library for theming existing websites

Windows
Windows Command Line Shutdow - A tool to shutdown Windows Computer from Command Prompt
gform - An easy to use Windows GUI toolkit for Go
go-Windows-begin - for the absolute Windows-Go beginner
go-ole - win32 ole implementation for golang
w32 - Windows API wrapper for Go.
walk - "Windows Application Library Kit" for the Go Programming Language

Unix
unixsums - Legacy Unix checksums: cksum, sum

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Twackup - Backs up your tweets into local files
domainerator - Command line tool to combine wordlist and suffixes/TLDs into domain names and check if they are registered or not
ebml-go - EBML decoder
gmail2go - Simple gmail multiple accounts cli mail checker
go-bindata - Converts any file into manageable Go source code for embedding binary data into a Go program.
go-cron - A small cron job system to handle scheduled tasks, such as optimizing databases or kicking idle users from chat. The cron.go project was renamed to this for go get
compatibility.
go-gmetric - Ganglia gmetric protocol support
go-nat-pmp - A client for the NAT-PMP protocol used in Apple and open-source routers
go-osx-xattr - Package xattr wraps OS X functions to manipulate the extended attributes of a file, directory and symbolic link.
go-webfinger - Simple Client Implementation of WebFinger
go.psl - Go regdom-libs/public suffix list
goconsistenthash - Consistent hashing library (based on http://www.lexemetech.com/2007/11/consistent-hashing.html)
godebiancontrol - Golang debian control file parser
gographviz - Graphviz DOT language parser for golang
golor - golor is a command line tool for golang source code coloring
golsys - A library for building an evaluating Lindenmayer systems.
gopcapreader - Presents realtime pcap data as io.Reader objects
gostax - A Streaming API for XML (StAX) in go
httptail - tools push stdout/stderr to http chunked
humanize - formats large numbers into human readable small numbers
humanize-bytes - Command-line utilities to convert "MiB" etc to raw numbers, and back
img-LinuxFr.org - A reverse-proxy cache for external images used on LinuxFr.org
netstat-nat - Display NAT entries on Linux systems
seed - Easily seed PRNGs with some entropy
spellabc - Package spellabc implements spelling alphabet code word encoding.
stressdisk - Stress test your disks / memory cards / USB sticks before trusting your valuable data to them
strftime - strftime implementation
validation - Simple independent struct/key-value validation