(Yet Another Compiler Compiler) A Unix compiler used to create a compiler. The operators, variables and constants of the program are typically defined in C using lex (LEXical analyzer), which converts them into preprocessed, machine-readable tokens for yacc. The grammar of the new language is written in C and compiled in yacc. The combination of lex (define elements) and yacc (define actions) creates a new compiler. For more information, visit www.epaperpress.com. See bison.