The PPAML project yielded a lot of cool work, I think that many people are still figuring out the most impact use case. I believe that the most mature new production language is Figaro, out of Charles River. They have some good example projects and a introductory text for their language.

https://www.cra.com/technical-expertise/probabilistic-modeli...

https://www.amazon.com/Practical-Probabilistic-Programming-A...

That being said, I'm very happy that Hakaru is getting attention.

If you're more familiar with JavaScript then checkout WebPPL. * made by the same people as 'church'

If you're more familiar with Haskell, then checkout hakaru.

If you are more familiar with Scala, or Java, checkout figaro. * has associated textbook https://www.amazon.com/Practical-Probabilistic-Programming-A...

If you're more familure with Clojure, then checkout 'Anglican'