DeepTest is a new library that allows you to run test suites in separate processes simultaneously. The obvious benefit is that on multiple core machines, as are becoming hip with the kids nowadays, test performance can be increased significantly. Initial tests by the developers showed that a test suite ran in half the time on a dual core machine, although real life performance is bound to vary.

With the perennial complaints from developers of how long test suites take to run, DeepTest looks like a promising development. The developers say they're looking at implementing a similar system for RSpec in future.