Istanbul - Code Coverage Tool - Istanbul is an all-javascript instrumentation library that tracks statement, branch, and function coverage.
JaCoCo - JaCoCo is a free Java code coverage library.
Blanket.js - Blanket.js is a JavaScript code coverage library that works both in-browser and with nodejs.
SimpleCov - SimpleCov is a code coverage analysis tool for Ruby.
SonarQube - SonarQube, a core component of the Sonar solution, is an open source, self-managed tool that systematically helps developers and organizations deliver Clean Code.
dotCover - JetBrains dotCover is a .NET unit test runner and code coverage tool that integrates with Visual Studio.