Wakie - Get Instant phone advice from peers
ElasticSearch - Elasticsearch is an open source, distributed, RESTful search engine.
Ninfex - Experimental people-powered search engine
Logz.io - Logz.io provides log analysis software with alerts, role-based access, unlimited scalability and free ELK apps. Index, search & visualize your log data!
Expertrec - Adds super fast search autocomplete, spell correct and search listing pages to your site search.
Searchkick - Intelligent search made easy with Rails and Elasticsearch - ankane/searchkick