I have to prefix this with the fact that I've only barely touched Chicken. I've been using Gambit for a few months. Performance: See benchmarks above. FFI: G

I have to prefix this with the fact that I've only barely touched Chicken. I've been using Gambit for a few months. Performance: See benchmarks above. FFI: Gambit's is very clean. I've used this extensively, and people that are doing iPhone/Objective-C stuff with it are using the FFI. I can't comment on Chicken's FFI. Libraries: I'm guessing Chicken wins here. The egg system seems more developed and has more packages than Gambit's Black Hole. Installation: I know Gambit is painless on Linux and Mac. I can't speak to Windows nor to which Linux distros package it. Licensing: I have to correct you here. Gambit is dual licensed: LGPL 2.1 and Apache 2. Support: Chicken's community and IRC room seem active. Gambit's are too; detailed answers are rapid on the mailing list.