[microtonal]

And if I can throw in another shameless plug (only because I think it will genuinely be of interest, of course), I'll point out this post[3] on Prolog resources, since Prolog often find application in the NLP world

You missed the nicest and most satisfying book ;):

http://www.mtome.com/Publications/PNLA/pnla-digital.html

It is simultaneously an introduction to Prolog and natural language parsing using Prolog.

[mindcrime]

Very cool. That post was originally written quite some time ago, and it was never meant to be an exhaustive list. That said, I'll add this to the list as well. Thanks for the pointer!