2. I'm specifically interested in making Arc (or Lisp in general) a good option for doing everything that you'll ever need to do. I think making games is a good thing to aim for: it's worth doing in itself (I like games, and there's one old no-longer-being-developed game I'd really like to implement myself), and it implies handling graphics, audio, and keyboard/mouse input, plus respectable execution speed. Seems either one could focus on the Racket libraries (I've found them pretty good but somewhat buggy and slow), learn to use the Racket FFI, or use Arc as a skin over a completely new platform or language. I'd be pleased to hear of progress in these domains. Any other topics are good too, though.
3. I could talk about various things I've done in Arc, and the ad hoc libraries I've constructed in the process. In the category of math, I'll quickly mention primality testing, modular exponentiation and inversion, prime factorization, polynomial arithmetic and interpolation, multiple-variable polynomial arithmetic, and integer nth roots of arbitrarily large real and complex integers.
