This document describes SPUR Lisp a Common Lisp superset designed and implemented at U.C. Berkeley. Function calling sequences, system data structures, memory management policies, etc. are all described in detail. Reasons for the more important decisions are given. SPUR Lisp is implemented in BARB, a software simulator for SPUR hardware. In addition to describing the design of SPUR Lisp, this paper provides documentation for the BARB simulator, the SPUR Lisp compiler, and associated tools.