|Developer(s)||Yukihiro Matsumoto (among others)|
|Stable release||2.0.0 / February 24, 2013|
|Type||Ruby programming language interpreter|
GNU General Public License
Matz's Ruby Interpreter or Ruby MRI (also called CRuby) is the reference implementation of the Ruby programming language. Until the specification of the Ruby language in 2011, the MRI implementation was considered the de facto reference. The RubySpec project has created a large test suite that captures 1.8.6/1.8.7/1.9 behavior as a reference conformance tool. Ruby MRI 1.9.2 currently passes over 99% of RubySpec.
The latest stable version is Ruby 2.0.0.
Yukihiro Matsumoto ("Matz") started working on Ruby on February 24, 1993, and released it to the public in 1995. "Ruby" was named as a gemstone because of a joke within Matsumoto's circle of friends alluding to the name of the Perl programming language.
The current stable version of the interpreter 2.0.0 was released on February 24, 2013.
Licensing terms 
Prior to release 1.9.3, the Ruby interpreter and libraries have been distributed disjointedly (dual licensed) under the free and open source licenses GPL and Ruby License. In release 1.9.3, Ruby's License has been changed from a dual license with GPLv2 to a dual license with 2-clause BSDL.
Operating systems 
Ruby MRI is available for the following operating systems:
This list may not be exhaustive.
Commonly noted limitations include:
- Performance -- the C Ruby interpreter's performance trails that of comparable languages such as Perl, and Python, mainly because of the design of the interpreter: To execute Ruby code, the interpreter builds a syntax tree from the source code and then evaluates the syntax tree directly, instead of first compiling it into more efficiently executable form. However, starting with version 1.9, Ruby switched to the YARV interpreter, whose performance is comparable to that of PHP.
- Backward compatibility -- version 1.9 and 1.8 have slight semantic differences.
- Ruby 1.9.2 is released
- Ruby 2.0.0-p0 is released
- An Interview with the Creator of Ruby
- Musha, Akinori (2008-05-26). "Ruby Core: Ruby 1.8.7-preview4 has been released". Retrieved 2008-05-30. "The new version of Ruby includes many bug fixes, lots of feature enhancements and some performance improvements since 1.8.6 while maintaining stability and backward compatibility with the previous release to a high degree, although there are ongoing efforts that need to be done toward adopting RubySpec."
- "1.8.7 NEWS". Retrieved 2008-05-30.
- Ruby License (ruby-lang.org)
- Ruby 1.9.3 Release News
- Ruby Performance Revisited - Joel on Software
- Boxplot Summary | Ubuntu : Intel Q6600 Computer Language Benchmarks Game
- InfoQ: Ruby 1.9 released