FELIX is a special purpose CAS consisting of three layers: i) a small C-kernel, ii) a programming language including interpreter, compiler and linker, and iii) a module library of algebraic algorithms. The central application is Buchberger's algorithm with emphasise on its extensions to non-commutative rings and modules.
Citation:
J. Apel and U. Klaus. FELIX - an Assistent for Algebraists. Proc. ISSAC'91 , ACM-Press (1991), 382 - 389.