MU-Prolog implementation

MU-Prolog was implemented in the early 1980's. Its an interpreter written in C and was ported to many UNIX systems over the years. It is now more or less oblolete but may be of historical interest. It ran at about 1.5K LIPS on a VAX (remember them?), compared to about 2K LIPS for CProlog, which used similar implementation technology - a structure sharing interpreter.

In its day it was quite an innovative system.

It was the first system with flexible and easy to use facilities for coroutining without a major efficiency penalty. Wait declarations allow programmers to specify when calls to procedures should proceed or delay based on how instantiated they are. A tool was implemented to automatically generate these declarations and reorder code to improve termination and efficiency in many cases.
It had the best facilities for soundly implemented negation and the first "pure" all solutions predicate. Negated and conditional goals delay until they are ground and an inequality predicate supporting (implicit) universal quantification is supported.
It was one of the first Prolog systems which was connected to database systems. Provided with the system is code to implement disk-resident relations supporting partial match retrieval. It was used for one of the very early deductive database systems.
It was one of the first Prolog systems with a form of module system.
It was the first Prolog system to use "executable" saved states and many other UNIX-friendly features.
It was one of the first Prolog systems to support dynamic loading and linking of object files from C and other languages.

It was used as a vehicle for experimenting with many aspects of language design, implementation, program transformation, deductive databases and debugging. After the invention of the Warren Abstract Machine the time was right to move on. Development of MU-Prolog was stopped in the mid 1980's when NU-Prolog, a compiled Prolog system, was designed and implemented.

The most complete reference for MU-Prolog is my thesis:

@book{naish:thesis:86,
        author =        {Naish, Lee},
        title  =        {Negation and control in {Prolog}},
        series =        {Lecture Notes in Computer Science},
        publisher =     {Springer-Verlag},
        address =       {New York},
        number =        {238},
        year   =        {1986},
        pages  =        {119},
        comment = {Technical report 85/12, Department of Computer Science,
                University of Melbourne}
}

Lee