This is a json parser, written in ruby. It has no dependencies other than ruby. See the file tested-on for a complete list of ruby interpreters used for testing. This library is intended to be "vendored". It is not a gem; instead, copy okjson.rb into your project and "require" it directly. This method helps you avoid an external dependency. It's only about 530 lines of source; about half of that is UTF-8 coding. OkJson is not particularly fast or flexible, but it is designed to be simple and portable. It should suffice for most needs. Patches to increase the correctness, readability, or portability of the source code will be gratefully accepted. Other patches likely won't. To Test: $ ./rubies ruby rbx /opt/ruby192/bin/ruby (Note: these tests originated at https://github.com/genki/json but have been changed to follow RFC 4627 and revised substantially.) To Use: OkJson.encode({"abc" => [123, -456.789]}) => "{\"abc\":[123,-456.789]}" OkJson.decode('{"abc":[123,-456.789e0]}') => {"abc"=>[123, -456.789]} That's it.