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.
Coverity Scan - Find and fix defects in your Java, C/C++ or C# open source project for free
Prettier - An opinionated code formatter
ESLint - The fully pluggable JavaScript code quality tool
Checkmarx - The industry’s most comprehensive AppSec platform, Checkmarx One is fast, accurate, and accelerates your business.
CodeClimate - Code Climate provides automated code review for your apps, letting you fix quality and security issues before they hit production. We check every commit, branch and pull request for changes in quality and potential vulnerabilities.