I don't think this language is called 'chicken' but rather 'chicken chicken', which is a bit confusing. I expected some kind of extension language built on top of chicken scheme but no, just no scheme and way more chicken.
It might be funny to also have a 2 symbol language called 'duck duck goose' where statements are terminated by 'goose' or something. I can't see any confusion between that and, say, duck duck go either!
I was also dismayed to find out that rather than being a mainstream post about my favorite little scheme... I'm greeted by an esoteric language of the same name.
It depends on how you use Racket, since it is actually a family of languages, but if you use R5RS I would say it should be really easy to port apps between them. And the community is great so I don't think you would have problem picking it up
google search: "chicken programming language" returns:
#1 Chicken (scheme implementation) http://en.wikipedia.org/wiki/Chicken_%28scheme_implementatio...
#2 CHICKEN Scheme http://www.call-cc.org/