Mondrian is a cross-platform project-manager and editor for the Ruby language. Written in 100% native Ruby using the FOX GUI toolkit, Mondrian has the familiar look and feel of a modern IDE while remaining dedicated to the uniqueness of the Ruby language and its community. Some features include: -a dynamic object browser -runtime error integration -a full-featured project manager -syntax highlighting
Is open source (MIT license).
(There aren't a good ruby ide in ubuntu... please, make a .deb package of this ide!!!)