This reminds me… some time ago I made my own Firefox extension to do full-text search of all my webpages. It’s in three parts: a server running in the background to interface with an SQLite database, a minimal extension to send text to that server, and a little GUI to query the database.
Unfortunately, all this makes it an utter pain to set up. It’s also somewhat specialised to my own very minimal needs. When I’ve mentioned it in the past, people have suggested open-sourcing it, but for these reasons I’ve resisted it. This post now makes me wonder if I should look into ways to improve it…