Graffiti CMS has been open sourced and added to Codeplex. They have two development branches, Graffiti CMS 1.3 which is probably a bunch of small fixes and improvements from 1.2 and Graffiti CMS 2.0. Check it out here: http://graffiticms.codeplex.com/.
At the time of this writing, looks like the site was taken down for maintenance. Hopefully it will be back up with new and exciting changes. At last look the latest binary release was 1.3. I think the latest stable release is 1.2, which is the version I have running on my Home Server.
If you want to know how to setup Graffiti CMS 1.2 on your Windows Home Server just follow the instructions from WeGotServed.com: http://www.wegotserved.com/2008/11/12/how-to-host-a-blog-on-windows-home-server-with-graffiti/. I'm not sure how accurate they will be anymore given the move to Codeplex but there might be a few.