Typesense
Open-source search engine built for lightning-fast search-as-you-type with typo tolerance baked in — a lighter alternative to Algolia and Elasticsearch.
Started as a side project around 2015 by Kishore Nallan, later incorporated under Jason Bosco. The ambition was a middle path: Elasticsearch is powerful but heavy to run, Algolia is slick but closed and pricey. Typesense keeps the whole index in memory, typically answers in under 50 milliseconds and is tuned right out of the box — no fiddling with analyzers to get typo-tolerant search.
The core is open under GPL v3, with Typesense Cloud as the paid hosted service. It now also supports vector search for semantic matching. The niche is clear: for anyone who wants Algolia's feel without Algolia's invoice.