Optimizely - A/B testing you'll actually use.
Pagewiz - An innovative landing page platform that lets you create, publish, and split-test landing pages.
Adobe Target - Adobe Target provides an intuitive user interface and an expanded personalization toolset.
AdBasis - A/B and multivariate ad testing software
invesp Pii Testing Engine - invesp Pii testing engine offers A/B testing solution for site optimization.
GrowthGiant - GrowthGiant enables marketers to increase their website sales and conversions by continuous A/B testing.