http://users.alliedmods.net/~kyles/builds/SteamWorks/
They may not even work, but they're there, now.
Huge thanks to:
Drifter - amb2 support
psychonic - all of the buildbots/slaves, added the SW sdk, fixed environ variables.
asherkin - buildbot general info
dvander - credentials/magic mac command.
The environment to my knowledge is SW 1.31.