Sphinx does indeed a very good job and is continuously improved. It is very fast and with small memory footprint. We also built https://techusearch.com https:/

Sphinx does indeed a very good job and is continuously improved. It is very fast and with small memory footprint. We also built https://techusearch.com https://techusearch.com which uses Sphinx indexes (think of a SaaS version of Elasticsearch backed by Sphinx).