Download of (TortoiseMerge-1.9.7-sl.pdf: 451,055 bytes) will begin shortly. If not so, click TortoiseMerge-1.9.7-sl.pdf.
TortoiseSVN is a Subversion (SVN) client, implemented as a windows shell extension. Which means it's available right where you need it: in the Windows file explorer.
It's intuitive and easy to use, since it doesn't require the Subversion command line client to run. Simply the coolest Interface to (Sub)Version Control!