Ruby
3 credits
01.11.10 - 05.09.10
How to Install Ruby in OSX
Install XCode
Go to the Mac App Store and download XCode. It will take a while to download because at the time of this writing it is about 3.5 GB.
Once it's downloaded, install it.
When XCode is installed, start it up and go to the XCode menu, select preferences, and then choose downloads. There you'll see an option to download the command line tools. Download those tools and then when it's complete quit out of XCode.