Zinc is a search engine that does full text indexing. It is a lightweight alternative to elasticsearch and runs in less than 100 MB of RAM. It uses bluge as the underlying indexing library.
It is very simple and easy to operate as opposed to elasticsearch which requires a couple dozen knobs to understand and tune.
It is a drop-in replacement for elasticsearch if you are just ingesting data using APIs and searching using kibana (Kibana is not supported with zinc. Zinc provides its own UI).