Aubrey Jaffer is a mathematician who has written several free software programs, such as the SCM Scheme implementation, which forms the core of GNU Guile, and the SLIB portable Scheme library. A mathematician is a person whose primary area of study and research is the field of Mathematics. Free software or software libre is Software that can be used studied and modified without restriction and which can be copied and redistributed in modified or unmodified SCM is a Free software Scheme implementation in C written by Aubrey Jaffer, the same author as the SLIB Scheme library and the Scheme is a Multi-paradigm programming language. It is one of the two main dialects of Lisp and supports a number of programming paradigms but is GNU Guile is an interpreter / Virtual machine for the Scheme programming language. SLIB is a Scheme Library written by Aubrey Jaffer which uses only standard syntax and consequently works on many different Scheme implementations such