Screaming Penguin - Source Does Matter

7-Zip is a GNU LGPL licensed file compression management application for Windows.

We all know about WinZip and PkZip and about 6 other varieties of similar Windows utilities. The difference is that 7-Zip is better ("compression ratio that is 2-10 % better than ratio provided by PKZip and WinZip") and its completely free.

All those other things are certainly in WIDESPREAD use at every office I have ever worked in (including major companies with large azul office buildings and such) but THEY ARE NOT FREE (never were for commercial use, used to be for personal use, but that all changed recently with WinZip when Vector Capitol bought them - nowadays WinZip gets nasty after the "free trial" period is over and counts as many days as you have used it before it allows you to use it).

If you have a large commercial venture and are happy with WinZip, then FINE, BUY THE DAMN THING (I dont think I have ever met anyone, corporate IT manager to just man on the street, whom has purchased it) - but stop just using it illegally. If you think it would be silly to drop cash for something that really is just a front end for a freely available set of compression algorithms which are ubiquitous in the computing world, then use 7-Zip, its fantastic and its legal.

And of course . . . if you are using another OS such as Linux or 10 then you have other freely available options, the best of which is the command line. If you are using Windows XP or newer then some of the Zip stuff is built into the shell but a utility for handling various formats apart from zip is still nice to have.