Presents the results of an investigation into the issues raised by the development of a compiler for APL, a very high level computer programming language. APL presents a number of novel problems for a compiler writer: weak variable typing, run time changes in variable shape, and a host of primitive operations. Through the integration of several recently developed compiler construction techniques, such as data flow analysis, and a novel and space efficient demand driven or lazy evaluation approach to code generation, the author has been able to produce a true compiler for the language while still maintaining the felxibility and ease that are the hallmarks of APL.