A Lisp machine (or LISPM) is a computer which has been optimized to run lispefficiently and provide a good environment for programming in it. The original Lisp machines were implemented at MIT, with spinoffs as LMI (defunct) and Symbolics (bankrupt). Xerox also had a series of Lisp machines (Dandylion, Dandytiger), as did Texas Instruments (TI Explorer). The TI and Symbolics Lisp machines are currently available as cards that fit into Macintosh computers (the so-called "Lisp on a chip").
Optimizations typical of Lisp machines include:
- Hardware Type Checking. Special type bits let the type be checked
efficiently at run-time.
- Hardware Garbage Collection.
- Fast Function Calls.
- Efficient Representation of Lists.
- System Software and Integrated Programming Environments.