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.
Splitly - Splitly is an A/B testing tool for Amazon FBA sellers.
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.
Amazon CloudSearch - Amazon CloudSearch is a fully-managed service in the cloud that makes it easy to set up, manage, and scale a search solution for your website.