An extension of RuboCop focused on code performance checks.

Knapsack Pro gem splits tests across parallel CI nodes and makes sure that tests run in optimal time

Better error page for Rack apps

A Ruby code quality reporter

Code smell detector for Ruby

Flay analyzes code for structural similarities. Differences in literal values, variable, class, method names, whitespace, programming style, braces vs do/end, etc are all ignored.

Code coverage for Ruby with a powerful configuration library and automatic merging of coverage across test suites

Guard::RSpec automatically run your specs (much like autotest)