PKZIP

The program stacks up well against Winzip in its ability to compress and e-mail files in a couple of clicks and integrate with third-party antivirus scanners. In addition, PKZip can create and extract files from many of the most common archive types. The program also offers 128-, 192-, and 256-bit AES encryption to keep your archives private from all but the most determined snoops, and lets you digitally sign them to certify that they are actually from you.

On the down side, it lacks Winzip's backup capabilities and it can't create self-extracting archives.

--Scott Spanbauer