Version 1.7.1 makes a copy of the source file before compressing, therefore requiring up to twice the size of the source file to be free on the destination drive (if compression level = store).

You can only add a single file to a .7z archive with this program?? I tried dragging multiple files to the 7zX icon, it 7-zips them up individually. What's the use of that? I've used 7-zip on other OS's, you can add several files just like a ZIP archive. What am I missing?

Looks like it is the only archiver capable of uncompressing several zips to THE SAME DIRECTORY. All the others I've tried were creating folders.

Until v. 1.6.6 is released to fix the multi-archive creation bug, a workaround is using 7zip portable via Crossover (or another Wine).

There a bug in 1.6.5 on multi-volumes creation, see homepage.
According to the developer, this has been fixed in 1.6.6, which will be released soon.

Someone should add "7zip" as a tag or in the description, so that a search on "7zip" returns this app. Currently it is missing from the results list, even if it's the best freeware to create a 7z archive.
(Note: 7z apparently is the correct name, 7-zip is only one of the possible archiver to create a 7z archive.)

This software is great! It's easy to use and has very good compression and multi-volume support, I don't know what I should expect else of a free compress software.

I wanted to use the 7z compression but didn't care too much for this program. I ended up using BetterZip (http://macitbetter.com/) instead and like it better.

@jeriqo: The Unarchiver come pretty damn close.

I hope we'll get someday a tool that can extract every kind of archives.. shoudl'nt be too hard to make.
Maybe the next Finder...