TortoiseSVN - The coolest interface to (Sub)version control
groupy - Groupy enables you to drag and drop application windows together to group them together under a common tabbed interface.
SnailSVN - Similar to Tortoise SVN for Windows but integrated into Finder
QTTabBar - QTTabBar is an extension for Windows Explorer that brings tabbed browsing to Microsoft's file...
Xversion - Super easy enterprise class version control.
BrightExplorer - Add a tabbed interface to Windows Explorer.