Otter is a free and open-source semantic search engine for Hack Club projects. It indexes the Unified YSWS (You Ship, We Ship) database and lets you search thousands of teen-built websites, apps, games, websites, and hardware projects using vector embeddings, full-text, and trigram search. Filter results by user with the user:username syntax, use "quoted phrases" for exact matches, or browse every project on the explore page.