MACRO SPITBOL is the best-ever implementation of the SNOBOL4 programming language, the language defined by The Green Book.

Written in the 1970's, MACRO SPITBOL is coded in MINIMAL, an assembly language for an abstract machine. The instruction set is carefully defined to allow some latitude in its implementation, so that hardware operations favorable to string processing can be exploited.

The principal author is Prof. Robert B. K. Dewar of the Courant Institute of Mathematical Sciences (CIMS), at New York University. Robert is also well-known for his work on the Ada programming language, and is a co-founder of AdaCore.