TortoiseSVN - The coolest interface to (Sub)version control
Google Open Source - All of Googles open source projects under a single umbrella
SnailSVN - Similar to Tortoise SVN for Windows but integrated into Finder
SmallDevTools - Handy developer tools with a delightful interface
Xversion - Super easy enterprise class version control.
whatdevsneed - This is whatdevsneed.