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