RubyCreator is an effort to add Ruby language support to QtCreator IDE and aim to have most of the features you can find on QtCreator C++ support.
Believe me, the plugin is much better than the logo!
Features
Far more than just syntax highlighting!
Other features
Code navigation via F2, press F2 under a identifier and if there's a method with that name you will be there.
Code indentation.
Auto completion, type "if foo⏎" and get the "end" keyword placed for you and the cursor on the right place, works for every construct that needs an "end", not only "if".
Features inherited from QtCreator
Code navigation history, are you editing a file and pressed F2 to go to a function but now want to go back? Press ALT + Left/Right to go back/forward on code location you were.
Git (subversion, CVS, etc) integration, want to do a git blame? hold ALT and type GB, done.
Navigation on git blame/git log outputs, want to see some commit found on a git blame? just click on the hash.