Was looking for a way to extract a .rpm so I could look at the contents and came across this little beast. It did not manage to unpack the .rpm as it happens.
This is the file I tried to open,
http://ftp.altlinux.org/pub/distributions/ALTLinux/p6/branch/files/x86_64/RPMS/wmbday-0.3.1-alt5.x86_64.rpm
However I did install the program on my Arch set up and it seems to work really well for the few compressed archives I tried it on.
The article I found was here at nixCraft
https://www.cyberciti.biz/tips/e-tool-to-extract-rpm-rar-zip.html
which led me to the developers page,
https://martin.ankerl.com/2006/08/11/program-e-extract-any-archive/
Just another oddity brought to you by by my curiosity for the esoteric.