Can DOpus handle .gz files? They're gzipped Unix-type archives. I added the ".gz" extension to my "Archives" file group, but when I click on a .gz file I get a dialog asking me which application to use to open the file. The file contains Win, not Unix files. It's gzipped because the software originated on Unix and the makers gzip everything, even Win files.
I'd recommend 7-zip to open the archive.
7-zip.org/
There have been a few threads about 7-zip and a possible Directory Opus plugin for 7-zip in the past,
but as of now, as far as I know, there is nothing soon to be released.
I have hoped for more integral to dpous 7-zip support in the past.
Among other things, it's Unicode support could be helpful in creating international DOpus icon sets.
But .... asking Directory Opus to open All the archives 7-zip can open may be more than can be accomplished.
I don't really know, but I agree that the ability to open tar, gz, and tgz archives is important.
Support for .gz (and .tar.gz etc.) archives is coming but I can't say when exactly. (I have it working on my dev machine but there's still a bunch more work to do.)
For now, Scred's advise of using 7-zip is the best way to extract .gz archives in Opus.