Optimizely - A/B testing you'll actually use.
Adobe Target - Adobe Target provides an intuitive user interface and an expanded personalization toolset.
VWO - Use VWO to tweak, optimize & personalize your website with minimal IT help.
AB Tasty - AB Tasty is an all-inclusive platform for conversion rate optimization, personalization, customer activation, and testing.
Chartbeat - Chartbeat shows you real-time traffic to your website and allows you to set alerts for any downtime or spikes in traffic.
invesp Pii Testing Engine - invesp Pii testing engine offers A/B testing solution for site optimization.