|The Archive Menu||The Archive Menu||The Mount menu|
It's one of the features of 4Pane that you can "browse" inside a tar or zip archive without having to extract it (for compressed tars this works for compression by gz, bz2, xz and lzma). In fact browse is an understatement: you can do much more than just look.
Double-click on an archive (NB this only works for archives, not compressed files). You'll see that the dir-view changes to show the archive as the "root directory"; any subdirectories that the archive contains will appear beneath. The file-view will now be showing the archive's contents. Notice that the icon of each file or directory is somewhat ghost-like, to remind you that what you're seeing is "virtual".
You can do most of the things inside the archive that you'd be able to do outside, and in the same ways. So for example you can Cut and Paste files or subdirectories, either from a menu, shortcut or Drag'n'Drop; and you can do this within an archive, between the archive and the "real world", or even between two archives. Undo/Redo works.
Open and Open With appear to work as usual, but here there's a catch: to open foo.txt in kwrite, the text-file is first copied into a real, temporary file; then the temporary file is opened. So although the file isn't officially read-only, any changes that you make will be saved to the temporary file and then deleted. Be warned!
There are a few things that you can't do within an archive. You can't make an archive item a symlink target (it would be meaningless to try). You can't open the Properties dialog for an archive item. You can't create a new item inside the archive; however you can create a file or directory outside the archive, and then Move it in. And if you move a relative symlink within an archive or between archives, it doesn't keep pointing at its previous target.
There's one thing that you can do within an archive but probably shouldn't. Archives are happy to contain two files with the name, and so it's possible to paste a file into an archive directory more than once if you want to. However 4Pane has no way of distinguishing between such files, so if you delete or rename one, both are affected.
There's also an extra thing that you can do: highlighting one or more files and choosing Extract from Archive from the Context Menu allows you to extract just those files to the directory of your choice.