There's not much here, but at least you can download a prototype SQLite3 text-indexing library I wrote in early 2006.
Please note that it's a prototype, not a fully optimized library designed for use in a production environment. It has some significant inefficiencies that I'm aware of, haven't bothered fixing, and likely won't ever fix. Nevertheless, you may use it in a product according to the terms of the license included in the download if you wish. A smaller, faster solution is certainly possible, but if you need something for a demo tomorrow while you're waiting for a real solution, this might be just the thing.
Thanks to Shaver for hosting it.
PamG 11:18, 7 July 2006 (PDT)