yacc（Yet Another Compil er），是Unix/Linux上一个用来生成编译器的编译器（编译器代码生成器）。yacc生成的编译器主要是用C語言寫成的语法解析器（Parser），需要与词法解析器Lex一起使用，再把兩部份產生出來的C程序一併編譯。yacc本來只在Unix系統上才有，但現時已普遍移植往Windows及其他平台。-yacc (Yet Another Compiler Compiler), is a Unix/Linux on a compiler to generate compiler (compiler code generator.) yacc compiler-generated key is written in C language parser (Parser), need to be used together with the Lex lexical parser, and then created out of the two parts together compile C programs. yacc on Unix systems already have the only but is now widely transplanted to Windows and other platforms.