Coverity Scan - Find and fix defects in your Java, C/C++ or C# open source project for free
Really Good Emails - A large collection of good product email design.
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.
Good Email Copy - Email copy from great companies.
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.
Good Sales Emails - Best sales emails from great companies