Buildr
Buildr is a build system for Java applications. We wanted something that’s simple and intuitive to use, so we only need to tell it what to do, and it takes care of the rest. But also something we can easily extend for those one-off tasks, with a language that’s a joy to use. And of course, we wanted it to be fast, reliable and have outstanding dependency management.
All written in Ruby, and according to Tim Bray, a drop-in replacement for Maven.