Selenium - Selenium automates browsers. That's it! What you do with that power is entirely up to you. Primarily, it is for automating web applications for testing purposes, but is certainly not limited to just that.
Optimizely - A/B testing you'll actually use.
Beta Testing - Beta Testing is an all-in-one feature-rich technical testing solution created to help small to large size businesses test and enhance their products through insights.
VWO - Use VWO to tweak, optimize & personalize your website with minimal IT help.
DevTest - Test management solution for efficient quality assurance
Google Analytics - Improve your website to increase conversions, improve the user experience, and make more money using Google Analytics. Measure, understand and quantify engagement on your site with customized and in-depth reports.