Vespa was actually very cool at the time as a document-oriented search engine, occupying the same niche as Solr and elaborations of that like ElasticSearch. But I don't know if it's competitive today.
This blog post says it's "developed by Yahoo" which is I guess true. But it was originally an acquisition, largely developed by a team in Norway, and apparently most Vespa development still happens there.
This blog post says it's "developed by Yahoo" which is I guess true. But it was originally an acquisition, largely developed by a team in Norway, and apparently most Vespa development still happens there.