The GPars (Groovy Parallel Systems) project provides multiple abstractions for concurrent, parallel programming in Groovy and Java. Rather than dealing directly with threads, synchronization, and locks, or even the java.util.concurrent classes added in Java 5, the project allows you to think in terms of actors, data flows, or composable asynchronous functions (to name a few).
In this talk, I covered the basics of GPars, including what it's like to learn to use it. Although I've done a fair amount of concurrent programming, I've just started using GPars. As such, this talk should be suitable for Groovy beginners.