This is a JSON implementation as a Ruby extension in C.

This is a JSON implementation in pure Ruby.

The fastest JSON parser and object serializer.

Ruby C bindings to the excellent Yajl JSON stream-based parser library.

A common interface to multiple JSON libraries, including Oj, Yajl, the JSON gem (with C-extensions), the pure-Ruby JSON gem, NSJSONSerialization, gson.rb, JrJackson, and OkJson.

Really simple JSON and XML parsing, ripped from Merb and Rails.

A JSON implementation as a JRuby extension. You may now use the json gem directly.

A streaming JSON parser (generates SAX-like events) and "JSON Path" like implementation to parse small amount of data in a large JSON file.