[wannesm]

If you're interested in actual implementations, the website of the Probabilistic Programming Workshop offers an overview of actively developed languages:

http://probabilistic-programming.org/

[gtani]

Thx. also this

http://research.microsoft.com/pubs/173887/model-learner-popl...

http://research.microsoft.com/en-us/projects/fun/

http://www.cs.tufts.edu/~nr/cs257/archive/avi-pfeffer/figaro...