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Lightweight Ruby
C Ruby Yacc C++ Batchfile Shell
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benchmark Remove benchmarks not in mruby
bin add mruby sources
doc/guides mruby-1.2.0
examples DISABLE_STDIO/ENABLE_DEBUG macros to rename; close #3014
include common.h are supposed to be included from other header, so call it wi…
lib/mruby Change to to make Ruby 1.9 Happy
mrbgems Implemented round(double) function within mruby-time gem, for it is m…
mrblib include changed from by quotes ("") to by brackets (<>); close #3032
src include changed from by quotes ("") to by brackets (<>); close #3032
tasks include changed from by quotes ("") to by brackets (<>); close #3032
test Bugfix nagative-number lshift() bit overflow
.gitignore Move guides location
.travis.yml travis-CI migration
.yardopts Improved mrb_args_format table
AUTHORS mruby-1.2.0 Fix typos in documentation and error messages [skip ci]
ChangeLog add document
LEGAL Change mruby-random License to MIT
MITL Update Coopyright Information to year 2015
Makefile remove trailing spaces
NEWS add document Update
Rakefile fix `rake doc` error
TODO update TODO entries; close #2831
build_config.rb Fix MRB_ENABLE_DEBUG_HOOK config typo left from 4440566
minirake Correctly handle relative paths
mruby-source.gemspec Switch gem API to constants only
travis_config.rb Enable full-debug build on travis using `MRB_ENABLE_DEBUG_HOOK`

Build Status

What is mruby

mruby is the lightweight implementation of the Ruby language complying to (part of) the ISO standard. Its syntax is Ruby 1.9 compatible.

mruby can be linked and embedded within your application. We provide the interpreter program "mruby" and the interactive mruby shell "mirb" as examples. You can also compile Ruby programs into compiled byte code using the mruby compiler "mrbc". All those tools reside in the "bin" directory. "mrbc" is also able to generate compiled byte code in a C source file, see the "mrbtest" program under the "test" directory for an example.

This achievement was sponsored by the Regional Innovation Creation R&D Programs of the Ministry of Economy, Trade and Industry of Japan.

How to get mruby

The stable version 1.2.0 of mruby can be downloaded via the following URL:

The latest development version of mruby can be downloaded via the following URL:

The trunk of the mruby source tree can be checked out with the following command:

$ git clone

mruby home-page

The URL of the mruby home-page is:

Mailing list

We don't have mailing list, but you can use GitHub issues.

How to compile and install (mruby and gems)

See the doc/guides/ file.

Running Tests

To run the tests, execute the following from the project's root directory.

$ make test


$ ruby ./minirake test

How to customize mruby (mrbgems)

mruby contains a package manager called mrbgems. To create extensions in C and/or Ruby you should create a GEM. For a documentation of how to use mrbgems consult the file doc/guides/ For example code of how to use mrbgems look into the folder examples/mrbgems/.


mruby is released under the MIT License.

Note for License

mruby has chosen a MIT License due to its permissive license allowing developers to target various environments such as embedded systems. However, the license requires the display of the copyright notice and license information in manuals for instance. Doing so for big projects can be complicated or troublesome. This is why mruby has decided to display "mruby developers" as the copyright name to make it simple conventionally. In the future, mruby might ask you to distribute your new code (that you will commit,) under the MIT License as a member of "mruby developers" but contributors will keep their copyright. (We did not intend for contributors to transfer or waive their copyrights, Actual copyright holder name (contributors) will be listed in the AUTHORS file.)

Please ask us if you want to distribute your code under another license.

How to Contribute

See the contribution guidelines, and then send a pull request to We consider you have granted non-exclusive right to your contributed code under MIT license. If you want to be named as one of mruby developers, please include an update to the AUTHORS file in your pull request.

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