Nosto - Personalized shopping experiences for e-commerce businesses
RetailRocket - RetailRocket offers personalization and product recommendation engine for eCommerce.
Hawk Search - Site-search engine for eCommerce platforms.
Dynamic Yield - Personalization & customer experience management
Algolia - Algolia's Search API makes it easy to deliver a great search experience in your apps & websites. Algolia Search provides hosted full-text, numerical, faceted and geolocalized search.
RichRelevance - MyBuys