Name Stalker 1.1 for Windows, Macintosh and Mac OS X was released on 6/16/2003.

Name Stalker is a domain management/tracking tool used to track domains you
own, or “stalk” domains you don’t own.

It’s 100% free for use with up to 100 domains and can be downloaded from:

Version 1.1 adds support for registrar status tracking, tracking of
projected release date, updating parsing code, and a few other feature