I was prepared to accept code, pseudocode, and English descriptions, and then translate them into coffeescript myself.
I did it last time and it was pain in the arse. It's fun to code one PD agent, not so much when they are forty and you must follow descriptions which you are not sure that you understand correctly.
I have written an interpreter which evaluates functions written in a lisp-like prefix notation, which was originally intended to be used in a program evolving automatic traders using genetic algorithms and real stock exchange data - the traders were represented as functions. Changing it to be applicable to PD simulations would be quite easy. Mutations are already coded too.
The idea of simulating opponents was mentioned in the discussion and relates to all sorts of LW decision theory idiosyncrasies. I think it's worth doing, even if it were as primitive as having a function "simulate(X)" which would return the result of the opponent's decision function where all instances of "simulate" are replaced by X (which is either C or D).
even if it were as primitive as having a function "simulate(X)"
I'm toying with each Bot having a "simulated" flag, and at the beginning of each game, create a real and a simulated version of each Bot, and let both Bots look at what the simulated Bots are doing. Haven't thought properly about it yet, but the rest of the project is coming along much faster than I'd anticipated so I'll have time to dig into this problem soon.
EDIT: I think I can do better. If bots have a single source code in some language L, and inferior interpreters I-...
Last year, there was a lot of interest in the IPD tournament with people asking for regular events of this sort and developing new strategies (like Afterparty) within hours after the results were published and also expressing interest in re-running the tournament with new rules that allowed for submitted strategies to evolve or read their opponent's source code. I noticed that many of the submitted strategies performed poorly because of a lack of understanding of the underlying mechanics, so I wrote a comprehensive article on IPD math that sparked some interesting comments.
And then the whole thing was never spoken of again.
So now I'd like to know: How many LWers would commit to competing in another tournament of this kind, and would someone be interested in hosting it?