GPars library is powerful, very simple to use, well designed and it brings advanced threading concepts like DataFlows, Agents and Actors formerly only sparsely available in Scala, Clojure to the Groovy world.
I use GPars in my project for a billion dollar product and services company in North America. Our application performs 14 to 20 million transactions a day which involves web service, complex computations and database calls. GPars library is solid and works like a charm. With this library, our application code is much shorter, clean and easier to maintain.
My work life is much easier after using Agents for monitoring and collecting stats on large batch processing jobs, and using Data Flow Queues and Tasks for adding and consuming jobs with just a few lines of code. And we got awesome support from firstname.lastname@example.org
GPars is awesome. Generally dealing with threading and concurrency is a real pain. With GPars you can get some very usable concurrency going in 3 lines of code.
Andrzej Grzesik - eCircle, development env lead