An anonymous reader writes: Today version 2.0.0 of Ruby has been released. This is a stable release, and the Ruby team has done their best to make it compatible with 1.9, making it easier to migrate than it was to switch from 1.8 to 1.9. New core language features include: 'Keyword arguments, which give flexibility to API design; Module#prepend, which is a new way to extend a class; A literal %i, which creates an array of symbols easily; __dir__, which returns the dirname of the file currently being executed; and UTF-8 default encoding, which make many magic comments omissible.' Also new are libraries for lazy stream and for asynchronous exception handling API. The release includes a number of performance improvements and debug support for DTrace.