Sphinx (search engine) is described as 'Sphinx is a software search engine designed with indexing database content in mind. It currently supports MySQL, PostgreSQL, and ODBC-compliant databases as data sources natively. Other data sources can be indexed via pipe in a custom XML format' and is a Search Server in the Development category. There are more than 25 alternatives to Sphinx (search engine) for a variety of platforms, including Online / Web-based, Linux, Windows, Self-Hosted solutions and Mac. The best alternative is Openverse, which is both free and Open Source. Other great apps like Sphinx (search engine) are elasticsearch (Freemium), MeiliSearch (Free, Open Source), Algolia (Free Personal) and Apache Solr (Free, Open Source).
Solr is an open source enterprise search server based on Lucene search library, with XML/HTTP and JSON APIs. Its major features include powerful full-text search, hit highlighting, faceted search, dynamic clustering, database integration, and rich document handling.
OpenSearch is a community-driven, open source search and analytics suite derived from Apache 2.0 licensed Elasticsearch 7.10.2 & Kibana 7.10.2. It consists of a search engine daemon, and a visualization and user interface, OpenSearch Dashboards.