Huge fan of Elephant 2000. It shows just how far we still have in expanding the linguistic side of programming. I don't think anyone has implemented it, but I think you can see the influence in Dynamicland's RealTalk. Its keywords Wish and Claim are both speech acts. The fact that dynamic land has effects in the actual world through its words makes this fact seem to be far from a coincidence. Sadly, Elephant 2000 isn't in Bret's list of papers, so I can't be certain he has read it, but I'd be surprised to find out this is an accident.
Definitely recommend reading Searle or Austin on speech acts. Searle is definitely less jargon heavy and incredibly readable.