| ⌘T | go to file |
| ⌘⌃P | go to project |
| ⌘R | go to methods |
| ⌃G | go to line |
| ⌘KB | toggle side bar |
| ⌘⇧P | command prompt |
This installs a patched ruby 1.9.3-p327 with various performance improvements and a backported COW-friendly GC, all courtesy of funny-falcon.
You will also need a C Compiler. If you're on Linux, you probably already have one or know how to install one. On OS X, you should install XCode, and brew install autoconf using homebrew.