Goby - A new language helps you develop microservices
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Goby is an object-oriented interpreter language deeply inspired by Ruby as well as its core implementation by 100% pure Go. Moreover, it has standard libraries to provide several features such as the Plugin system. Note that we do not intend to reproduce whole of the honorable works of Ruby syntax/implementation/libraries.

One of our goal is to provide web developers a sort of small and handy environment that mainly focusing on creating API servers or microservices. For this, Goby includes the following native features:

  • Robust thread/channel mechanism powered by Go's goroutine
  • Builtin high-performance HTTP server
  • Builtin database library (currently only support PostgreSQL adapter)
  • JSON support
  • Plugin system that can load existing Go packages dynamically (Only for Linux by now)
  • Accessing Go objects from Goby directly

Note: Goby had been formerly known as "Rooby", which was renamed in May 2017.

Table of contents

Demo screen and sample Goby app

New! Check-out our sample app built with Goby. Source code is also available here.


Goby has several aspects: language specification, design of compiler and vm, implementation (just one for now), library, and the whole of them.

Language: Class-based, straight-ahead object-oriented script language. Syntax is influenced by Ruby language (and by Go a bit), but has been condensed and simplified (and slightly modified) to keep Goby VM simple and concise. Several aspects of Ruby such as meta-programming (known as 'magic'), special variables with $, or like that, have been dropped for now, but note that we might resurrect some of them with a different form or implementation in the future.

Class: Single inheritance. Module is supported for mixin with #include or #extend. Defining singleton class and singleton method are also supported. Goby has two kinds of class internally: native class and standard class. Native class (or builtin class) provides fundamental classes such as Array or String. Object class is a superclass of any other native/standard classes including Class class. Class class contains most common methods such as #puts. Standard class (or standard library) can be loaded via require and provides additional methods. Standard classes are often split internal Go code and external Goby code in order to make implementation easier. Both kinds of class are transparent to Goby developers and can be overridden by child classes. Any classes including Class class are under Object class.

Compiler: Consists of AST, lexer, parser, and token. Pretty conventional and should be familiar to language creators. These components are all written in 100% pure Go, instead of using conventional static yacc/lex/bison conversion with a mess of ad-hoc macros. This makes Goby's codes far smaller, concise, and legible. You can inspect, maintain, or improve Goby codes more easily, being free from pains like C/C++ era.

VM: YARV-conscious, including stack and call_frame, as well as containing Goby's native classes, plus some standard library and additional components. All are written in Go as well.

Implementation: Built-in monolithic Go binary executable which equips several native features such as a robust thread/channel mechanism powered by goroutine, a very new experimental Plugin system to manage existing Go packages dynamically from Goby codes, igb (REPL) powered by readline package. Goby contains some standard or third-party Go packages, but the dependency to them is not high. These packages contain no CGO codes (at least by now) thus cross-compile for any OS environments that Go supports should work fine.

Library: Provides some lean but sufficient standard libraries to support developers, including threaded high-performance HTTP server, DB adapter, file or JSON. Curiously, most of them are split into Go and Goby codes, and Goby codes are not within Goby executable but placed under lib directory as Goby script files. Of course you can create custom libraries and include them to your codes. Thanks to the flexibility of Plugin system, we expect that you can quickly import most of the existing Go packages to your Goby scripts without creating additional libraries from scratch in almost all cases.

Let's improve Goby together!: We are optimizing and expanding Goby all the time. Toward the first release, we've been focusing on implementing Goby first.


  • Plugin system
    • Allows to use Go libraries (packages) dynamically
    • Allows to call Go's methods from Goby directly (only on Linux for now)
  • Builtin multi-threaded server and DB library
  • REPL (run goby -i)


Perhaps Goby should be far easier for Rubyists to comprehend. You can use Ruby's syntax highlighting for Goby as well😀

  • Everything is object
  • Object and Class
    • Top level main object
    • Constructor
    • Class/instance method
    • Class
      • Inheritance
      • Singleton class is now supported
    • self
  • Module
    • #include
    • #extend
    • :: for namespace
  • Variable: starts with lowercase letter like 'var`
    • Local variable
    • Instance variable
  • Constant
    • Starts with uppercase like Var or VAR
    • global if defined on top-level
    • not reentrant
    • (special variables with $ are unsupported)
  • Methods
    • Evaluation with arguments
    • Evaluation without arguments
    • Evaluation with block (closure)
    • Defining singleton methods
  • Block
    • do - end
  • Flow control
    • if, else, elsif
    • while
  • IO
    • #puts
    • ARGV
  • Import files
    • require (Just for standard libraries by now)
    • require_relative
  • Thread (not a class!)
    • Goroutine-based thread method to create a new thread
    • Works with Channel class for passing objects between threads, like chan in Go
    • See this sample: One thousand threads

Native class

Written in Go.

  • Class
  • Integer
  • String
  • Boolean
  • Null (nil)
  • Hash
  • Array
  • Range
  • URI
  • Channel
  • GoObject (provides #go_func that wraps pure Go objects or pointers for interaction)

Standard library

written in Go and Goby.

  • Loadable class
    • File
    • DB (only for PostgreSQL by now)
    • Plugin
  • Loadable module


Confirmed Goby runs on Mac OS and Linux for now. Try Windows and let us know the result.

A. Via Homebrew (binary installation for Mac OS)

Note: Please check the latest release before installing Goby via Homebrew

brew tap goby-lang/goby
brew install goby

In the case, $GOBY_ROOT is automatically configured.

B. From Source

Try this if you'd like to contribute Goby! Skip 1 if you already have Golang in your environment.

  1. Prepare Golang environment 1-1. Install Golang 1-2. Make sure $GOPATH in your shell's config file( like .bashrc) is correct 1-3. Add you $GOPATH/bin to $PATH
  2. Run go get github.com/goby-lang/goby
  3. Set the Goby project's exact root path $GOBY_ROOT manually, which should be:

Verifying Goby installation

  1. Run goby -v to see the version.
  2. Run goby -i to launch igb REPL.
  3. Type require "file" in igb.

FYI: You can just run brew test goby to check Homebrew installation.

If you have any issue installing Goby, please let us know via Github issues

Using Docker

Goby has official docker image as well. You can try the Plugin System using docker.

Sample codes

More sample Goby codes can be found in sample directory.


Joining to Goby

Join us on Slack!

See the guideline.


  • @st0012
  • @hachi8833
  • @Maxwell-Alexius


Support Us


Support us with a monthly donation and help us continue our activities. [Become a backer]


(We'll release first beta version in August, please checkout this issue for what features Goby will support.)

Supporting Goby by sending your first PR! See contribution guideline

Or support us on opencollective (I quit my job to develop Goby in full-time, so financial support are needed 😢)


The followings are the essential resources to create Goby; I highly recommend you to check them first if you'd be interested in building your own languages: