TextMate is a text editor for Mac OS X.
In studio 3 much of this sort of functionality is still coming as aptana is going more of a textmate bundle route for a great deal of their features which i think is really cool
How to enable jQuery support in Aptana Studio 3
If you want something more minimalistic there is e text editor which supports textmate bundles not free though;i ve been using aptana it s quite good with lots of features even in the free version you probably don t need pro
What IDE / Editor do you use for Ruby on Windows?