I've read that article a number of times, it's of course a great data structure, though I haven't ever used it myself. I think I like b+tree/rope better though for indexing lists of things efficiently.

I did a lot work using b+tree in a bigger project that I could never quite finish. Finally gave up a year ago and grabbed leftover code to make Bike. Bike is using a pretty dumb data structure, but good enough for now. Hope one day to add back the more performant b+tree stuff.