Eventually all of these projects will be highlighted on Awesome F/OSS (https://awsmfoss.com), but for now I'm just going to dump my bookmarks here for other people, since I'm leaving awesome projects out:
Search Engines
AWS OpenSearch https://github.com/opensearch-project/OpenSearch
https://github.com/opensearch-project/OpenSearch-Dashboards
https://github.com/opensearch-project/perftop
https://github.com/go-ego/riot
https://groonga.org/ https://github.com/groonga/groonga
https://github.com/meilisearch/MeiliSearch
https://github.com/mosuka/bayard
https://github.com/nezaboodka/nevod
https://github.com/searx/searx
https://github.com/stryku/okon
https://github.com/toshi-search/Toshi
https://github.com/typesense/typesense
https://github.com/valeriansaliou/sonic
Algolia
https://github.com/marconi1992/algolite
https://github.com/quickwit-inc/quickwit
https://github.com/prabhatsharma/zinc
phalanx https://github.com/blugelabs/bluge https://github.com/mosuka/phalanx https://github.com/mosuka/blast
ManticoreSearch
https://github.com/manticoresoftware/manticoresearch
https://github.com/manticoresoftware/docker
https://manticoresearch.com/blog/manticore-alternative-to-el...
https://manual.manticoresearch.com/Introduction
https://forum.manticoresearch.com/t/manticore-search-cheatsh...
https://forum.manticoresearch.com/
Whoosh https://whoosh.readthedocs.io/en/latest/
https://pypi.org/project/Whoosh/
lyra https://github.com/nearform/lyra
https://nearform.github.io/lyra/
https://github.com/LyraSearch/lyra
flexsearch
https://github.com/nextapps-de/flexsearch#performance-benchm...
Lucene
https://github.com/apache/lucene
ZincSearch
Solr
https://solr.apache.org/operator/
https://solr.apache.org/guide/solr/latest/getting-started/so...
https://github.com/apache/solr
https://solr.apache.org/guide/solr/latest/deployment-guide/s...
Konnu https://gitlab.com/shadowislord/konnu
Quickwit QuickWit + Clickhouse
https://clickhouse.com/docs/en/guides/developer/full-text-se...
https://clickhouse.com/docs/en/sql-reference/functions/strin...
There is no way I can get to running all of these (this project was supposed to be quick!!), but I will run the ones I noted earlier, and probably manticore too since it was high on my list since it's quite polished looking.