Micro-Max is a chess engine developed by Dutch H.G. Muller, born in 1956.
The program is written in C
C (programming language)
C is a general-purpose computer programming language developed between 1969 and 1973 by Dennis Ritchie at the Bell Telephone Laboratories for use with the Unix operating system....
and according to IOCCC rules it is 1088 characters, not counting ; { } nor leading spaces and line feeds. The author claims that it is the smallest non-trivial chess engine in existence.
The source code for Micro-Max and other chess variant engines is available.