Jerbil FAQ

How do I install jerbil using gem ?

gem install jerbil --source http://code.trampolinesystems.com

What dependencies does jerbil have ?

Jerbil requires rubygems, rjb, rake and JDK 1.5.

How does Rake+Jerbil compare to Ant ?

Jerbil is just a set of extensions (tasklibs) for Rake, the build system used in most Ruby projects. Rake's syntax is a lot cleaner than Ant's XML based build files. At the same time it provides the user with a full programming environment, so things like conditions and branches don't have to be mapped to XML markup. See Martin Fowler's article for a good introduction. Most of the jerbil tasks (such as compiling, testing) run in one single Java VM, which makes jerbil very fast.

Why didn't you use JRuby ?

Performance. Laziness. You actually get a lot more flexibility when loading the JVM from within CRuby, as opposed to loading Rake from JRuby. In a JRuby scenario, by the time Rake gets executed the JVM has already been fully initialised, so you no longer have control over the bootstrapping process (classpath setup etc.). I'm sure there're ways to work around that, and JRuby's Java "integration" is obviously more powerful than Rjb's.

Is this actually used somewhere ?

We use it for our in-house software development, see Springy for an example.