Vespa has been around for a LONG time. When I worked at Yahoo back in 2005-2007 the Flickr team were using it to scale Flickr - they were integrating it in order to serve things like public tag pages, to take the load off their MySQL cluster.
I remember understanding it as the internal equivalent to something like Solr, although actually it predated it - looks like the first public Solr open source release (coming out of CNET) was January 2006.
I remember understanding it as the internal equivalent to something like Solr, although actually it predated it - looks like the first public Solr open source release (coming out of CNET) was January 2006.