Optimizely - A/B testing you'll actually use.
SiteGainer - SiteGainer is an A/B testing and conversion optimization platform.
Webtrends Optimize - Webtrends Optimize - a powerful, enterprise-grade Testing and Personalisation platform. AB, MVT & Server-side Testing, Product Recommendations & much more.
Experiment Engine - Experiment Engine is a A/B testing solution that harnesses human expertise to automate conversion optimization.
Evolv - Evolv is the visual editor for web-based projects that are used to find better ways to connect with customers in order to improve marketing economics.
Intellimize - Convert more. Optimize and personalize for every website visitor.