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.

Google Custom Search - Google Custom Search enables you to create a search engine for your website, your blog, or a collection of websites.

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.

ElasticSearch - Elasticsearch is an open source, distributed, RESTful search engine.

Morpheus - Morpheus is integration software designed to help major cloud infrastructure work in harmony. For example, if a company has assets on both Google's and Amazon's cloud services, Morpheus helps bridge the gap to improve productivity.

Searchly - Searchly offers elastic search as a service.