A combinator reduction evaluator with a translator from lambda calculus to combinators. The creative part was getting a C compiler to parse combinator expressions with the traditional syntax, where function application does not have an operator and is left-associative, like S K K. http://www.ioccc.org/years.html#1998_fanf
Winning an IOCCC contest is far from being useless though:-)
Hey, I've seen some of your IOCCC entries. Even had some fun trying to understand them back in the day.
IOCCC gang rise up. This is mine: https://www.ioccc.org/years.html#2005_persano
Somehow, I have a rather small one: https://www.ioccc.org/2012/kang/kang.c
I think I have submitted once or twice before that got won, and all other entries were excessively long to be honest. Guess a conciseness is a virtue.
> Guess a conciseness is a virtue.
Indeed; quoting from my winning entry [1] that same year:
> This program celebrates the close connection between obfuscation and conciseness, by implementing the most concise language known, Binary Lambda Calculus (BLC).
> The submission implements the universal machine in the most concise manner conceivable.
[1] https://www.ioccc.org/2012/tromp/hint.html