This is a subset of the Loop macros from CLtL2,
chapter 26. It is the subset written by Peter Norvig
in his book Paradigms of Artificial Intelligence
Programming. Case Studies in Common Lisp,
section 24.5.
VEOS is a user-level framework for prototyping distributed
applications. VEOS tools are controlled from Xlisp. By
Geoffry
P. Coco et al. of the Human Interface Technology Lab, University
of Washington, Seattle.