1. Elasticsearch is an open source, distributed, RESTful search engine.

  2. 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.

  3. Solr is an open source enterprise search server based on Lucene search library, with XML/HTTP and...

  4. Sphinx is a tool that makes it easy to create intelligent and beautiful documentation, written by...

  5. 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.

  6. Amazon CloudSearch is a fully-managed service in the cloud that makes it easy to set up, manage, and scale a search solution for your website.

  7. The simplest way to add search to your website or application. Sign up for free.

  8. SearchSpring is an eCommerce site search tool.

  9. 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.

  10. Doxygen is a tool for generating documentation from annotated C++ sources, as well as other popular...

  11. Xapian is an open source probabilistic information retrieval library, released under the GNU...

  12. Amazon Elasticsearch Service is a managed service that makes it easy to deploy, operate, and scale Elasticsearch in the AWS Cloud.