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.
Apache Solr - Solr is an open source enterprise search server based on Lucene search library, with XML/HTTP and...
Swiftype Site Search - Swiftype Site Search helps to sell more, get the right answer to more people on the platform and surface relevant content for readers and followers.
ElasticSearch - Elasticsearch is an open source, distributed, RESTful search engine.
Google Custom Search Engine - Google Custom Search is a platform provided by Google that allows web developers to feature specialized information in web searches, refine and categorize queries and create customized search engines, based on Google Search.
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.