AbTest.io - A free url shortener with A/B testing features
Glui - glui - GLUI is a GLUT-based C++ user interface library which provides controls such as buttons, checkboxes, radio buttons, and spinners to OpenGL applications. It is window-system independent, using GLUT or FreeGLUT.
GoodUI Evidence - People's A/B test results that show which UI ideas work best
Red Pen - Red Pen lets you upload your design, share a short URL, and get live, annotated feedback super-fast.
PreFlight - Preflight is an Automated Web Testing tool. Allows everyone to automate Web UI tests.
FLTDSGN - Daily showcase of the best flat UI design websites and apps