We just migrated from Merant PVCS to Subversion in December. I also use the Tortoise client, but others are free to use the client of their choice. Some use Tortoise, some use the "real" command line client. We love it, and I can already say we will not be going back, since I am the lead developer and keeper of the source control server. :-D FWIW: We run it on Windows 2000 (2003 when the new server arrives) and Apache 2, with the Windows authentication module.