Redcar is an open-source programmers' text editor for Ruby, written in Ruby. It is designed to be compatible with Textmate bundles

Redcar is an open-source programmers’ text editor for Ruby, written in Ruby. It is designed to be compatible with Textmate bundles (a work in progress) and run cross-platform on JRuby. Redcar is currently in the middle of begin ported to JRuby, please subscribe to get updates on our progress.
(Link: Redcar is an open-source programmers’ text editor for Ruby, written in Ruby. It is designed to be compatible with Textmate bundles)