Calling 7 zip as just an alternative to WinZip would be an insult to the software developers of 7 zip. It’s much better than Winzip. I was surprised to see that one of the archive files that Winzip reported as corrupt, 7zip unzipped it without any issue.
The other important point is that it supports a lot of archive formats –like ISO- that WinZip doesn’t. Here are some of the supported formats:
Probably WinZip should come out with some unique and exclusive option now, otherwise it would be just a matter of time before people would start flocking towards 7-zip.