No tool is an island, Subversion™ needs to integrate with the other tools you use on a day to day basis. For example, Subversion does not have its own graphical user interface, it is completely driven from the command line. Many developers like this but others prefer a GUI or a direct integration with their favorite IDE.

http://weblogs.asp.net/lhunt/archive/2006/08/21/Subversion-clients_2E002E002E00_.aspx

http://www.collab.net/products/subversion/tools.html