Is there a good open source alternative to WinZip or PKzip?

There seems to be a bewildering array of programs that zip and unzip files. Anybody have a recommendation? Thanks!

and very popular. I've seen it recommended often in freeware groups:

http://www.7-zip.org

Can't say I have personal experience with it, though. My preference is Iceows:

http://www.iceows.com

which is full-featured and free, but not open source.

If you have trouble, I'd be interested in hearing about it. Thanks.

It's gone through several revisions since I last used it, but when I was using it for testing purposes, I had occasional problems with it I couldn't explain. Discussing it in various forums, I found others had the same problem, on different platforms even, so I'm assuming it was a coding issue of some sort, possibly a flaw in the compression algorithm, but I don't know enough about how it works to suggest what it might have been.

Specifically, what would happen is that I could have two archives of similar size, somewhere in the hundreds of megabytes area, uncompress them, and one would fully uncompress in about a minute while the other would literally take hours. I had one I remember distinctly (because it was the last time I used it) that was ~700 MB. It took nearly 24 hours to unpack. I started it, left for work, came back, and it was still unpacking. Others of a larger size would unpack before I could make a trip to the refrigerator.

Like I said, this may be fixed now -- this was about six months ago -- but if it still has that issue, it's quite irritating.

Thanks. While we're sharing, here's a similar annoyance for Iceows users.

If you unpack a serialized RAR (one of those RAR archives cut into pieces, I don't know the actual word for it) and any of the parts are missing, Iceows will peg the CPU for anywhere from 3-20 minutes. It's the only problem I've encountered with the program, but it's a doozy. Count those files before clicking or you'll be taking a lunch break while your OS pretends it's wallpaper.

You'd think a simple check for the integrity of the archive would be rather simple.

I prefer using rar myself, even if it isn't Open Source. (Although, I think I have the source code for a command line version I use on my Linux boxes.) It's fast, has good compression, and allows you to mess with the archives in ways other archivers don't. In this context for example, it checks for the existence and integrity of each file before it starts processing and skips it if it is not present. It'll also take what data it can out of the archive even if it has errors and unpack what it can, assuming you set the right switch that tells it to do this...doesn't take any longer for it to do this either.