Departmental Papers (ESE)

Document Type

Journal Article

Subject Area

GRASP, Kodlab

Date of this Version

May 1992


Copyright 1992 IEEE. Reprinted from IEEE Computer, Volume 25, Issue 5, May 1992, pages 12-24.

This material is posted here with permission of the IEEE. Such permission of the IEEE does not in any way imply IEEE endorsement of any of the University of Pennsylvania's products or services. Internal or personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution must be obtained from the IEEE by writing to By choosing to view this document, you agree to all provisions of the copyright laws protecting it.

NOTE: At the time of publication, Daniel Koditschek was affiliated with the University of Michigan. Currently, he is a faculty member of the School of Engineering at the University of Pennsylvania.



Date Posted: 13 March 2008

This document has been peer reviewed.