A Subversion client,
implemented as a windows shell extension.
TortoiseSVN is a really easy to use Revision control / version
control / source control software for Windows.
Since it's not an integration for a specific IDE you can use it with whatever development tools you like.
TortoiseSVN is free to use. You don't need to get a loan or pay a full years salary to use it.
TortoiseSVN 1.7.12, built against Subversion 1.7.9. Released 04. April 2012.
Grab it from the download page.
Make sure to read the release notes first!