MSR's Probabilistic Programming Language R2 Released
research.microsoft.com
research.microsoft.com
Every programmer should read this paper. It's one of the nicely written paper than pretty much anyone can understand.
[1] http://research.microsoft.com/en-us/um/cambridge/projects/in...
edit: typo
First, infer.net is a DSEL of C# implemented as a library, while this is a new language. More substantially, infer.net is designed to use variational inference, which limits the class of graphical models that can be supported, while R2 seems to be based on sampling hence has no limits on the models it can represent. A more similar approach would be Church (http://projects.csail.mit.edu/church/wiki/Church), a probabilistic language based on Scheme.
Of course, the downside of sampling is that inference is orders of magnitude slower, and there's no principled way to know when it converges, that's why many people prefer variational inference.
I haven't read the article thoroughly enough to know if the samples are of the same quality.