* [Mocha v3.1.0](https://github.com/freerange/mocha) – Ruby library providing mocking and stubbing with unified syntax and support for multiple test frameworks.

* [mutant v0.15.1](https://github.com/mbj/mutant) – Ruby mutation testing framework that modifies code to confirm tests catch defects.

* [knapsack_pro v9.2.3](https://github.com/KnapsackPro/knapsack_pro-ruby) – Ruby gem that optimally parallelizes tests across CI nodes to significantly reduce execution time.