Charj is a language for productive parallel programming, based on the Charm++ runtime system. While its compiler is experimental in nature, it can be used to build and run simple programs.
To begin using Charj, you will need a (recent) version of Charm++ (present at CHARM_HOME), a JDK installation, and a SBT installation. Then, run the ./build.sh script from this repository, and refer to the instructions it generates throughout its execution.
Note, Charj's syntax has undergone numerous changes throughout the years. Where it was, historically, Java-based, it is now Scala-based. We occasionally use the term (Scala-)Charj to refer to the current iteration.
The most comprehensive documentation for Charj is Aaron Becker's PhD thesis. While its examples are based on the Java-based iteration of Charj, its ideas translate to the modern version of Charj found here.