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.
WHMCS - WHMCS is an all-in-one client management, billing & support system for online businesses.
ElasticSearch - Elasticsearch is an open source, distributed, RESTful search engine.
HostBill - HostBill is a powerful and flexible, all-in-one automation, billing, client management and support platform for online businesses.
Site Search 360 - Site Search 360 enhances and improves your built-in CMS or product search with autocompletion, semantic search, filters, facets, detailed analytics, and a whole lot of customization options.
Blesta - Blesta is professional client management, billing, and support software.