O'Reilly Network: [April 15, 2003] has a complete listing of Linux commands and example usage from agetty to znew.
If you don't use agetty I'm not suprized its usually called by init to set terminal parameters. And znew converts ".Z" zip files to ".gz" zip files of course.
If I start posting more of these straightforward links with only the briefest of comments, it's because I installed "bookmarklets". Which are only kinda working, but that's another story.