SLIP is a list processing computer programming language, invented by Joseph Weizenbaum in the 1960s. The name SLIP stands for Symmetric LIst Processor. It was first implemented as an extension to the Fortran programming language, and later embedded into MAD and ALGOL.[1] The best known program written in the language is ELIZA, an early natural language processing computer program created by Weizenbaum[2] at the MIT Artificial Intelligence Laboratory.[3]