Quizzes for Pages - Quizzes for Pages is an application to create and share quizzes on your Facebook Page.
Coverity Scan - Find and fix defects in your Java, C/C++ or C# open source project for free
Outgrow - Enabling marketers boost conversion with interactive, beautiful & viral quizzes/calculators.
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.
doopoll - Create live, instant, editable polls effortlessly
ReSharper - ReSharper is a productivity tool for visual studio that provides tools and features to help you manage your code.