Xapian is nice. I've used it before to add interactive autocomplete to a Python web app, since my previous favourite, Whoosh, is unmaintained and somehow slower than grep on a folder (I remember it being pretty fast years back, I'd love to know what happened).
I'd say my favourite thing about Xapian is that it's just a simple library you can embed in any app, no need for a separate database and JVM tuning. For simple usecases and small-to-medium datasets, it just works.
I'd say my favourite thing about Xapian is that it's just a simple library you can embed in any app, no need for a separate database and JVM tuning. For simple usecases and small-to-medium datasets, it just works.