ruby-from-other-languages

http://www.ruby-lang.org/en/documentation/ruby-from-other-languages/to-ruby-from-python/

http://www.ruby-lang.org/en/documentation/ruby-from-other-languages/to-ruby-from-java/

http://www.ruby-lang.org/en/documentation/ruby-from-other-languages/to-ruby-from-c-and-cpp/

http://www.ruby-lang.org/zh_cn/documentation/ruby-from-other-languages/to-ruby-from-python/

http://www.ruby-lang.org/zh_cn/documentation/ruby-from-other-languages/to-ruby-from-java/

http://www.ruby-lang.org/zh_cn/documentation/ruby-from-other-languages/to-ruby-from-c-and-cpp/