Z39.50
Information Retrieval Service Definition and Protocol Specification for Library Applications. Developed by NISO, this standard specifies an OSI application layer service to allow an application on one computer to query a database on another; it is used by WAIS

Z
A formal specification language developed at Oxford University for describing computing systems, based on set theory and predicate calculus

ZEBRA
A data management package in the CERN Program Library -

ZIP
One of the most commonly used compression formats for PC and UNIX based computers.

ZOG
A high-performance hypertext system developed at Carnegie-Mellon University.

zone
One or more domains in a DNS hierarchy or a db.name file.