I do Source Mapping but mostly for Portal and Portal 2. I'm the main mapper of Portal: Project-Beta, Blue Portals and I'm also a mapper for Portal: Alive and Kicking. I do mapping for other Source games such as Half-Life 2 also.
Map (vmf) files of the campaign from Portal: Project-Beta
Portal: Project-Alpha is back with the Steampipe fix, and new maps! Play some of the original portal with a alpha style. Portal: Project-Alpha now includes...
Blue Portals SDK + example files. Has all campaign maps, Extended Play maps, Conversion Cubed, prefabs and instances!