Codacy - Automatically reviews code style, security, duplication, complexity, and coverage on every change while tracking code quality throughout your sprints.

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.

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.

ESLint - The fully pluggable JavaScript code quality tool

CodeSonar - CodeSonar, produced by GrammaTech, is source and binary code analysis software that finds critical defects that can crash systems, result in unexpected operations, threaten security, and more.

SensioLabs Insight - PHP Project Quality Done Right.