LYSP: a Lisp dialect for programming small applications

Abstract

Some ten years ago, a small group of us at IBM Research undertook to write a new kind of text editor, to run in the VM/370 environment, based on our experience with the experimental Business Definition System (BDS) we had implemented previously. This new editor, called the Parametric Editor, or P-EDIT, was to be upwards compatible with an existing popular editor in use at that time, while providing the ability to edit multiple versions of a file simultaneously, and providing a general UNDO command which could be used to return to any previous state of the editing session, and which itself was UNDOable.