Cat.tar.gz
Proof that cats aren’t a liquid after all because liquids cannot be compressed.
Cats move between 3 states of matter at will. Solid when you need to move them from your chair, liquid when you need to pick them up, gaseous when they take up all available space in the apartment. Also occasionally plasma, if they’re sunbathing for too long
I kinda hope someone eventually reverse engineers rar compression
7-Zip can extract .rar just fine. It does not have a .cat extractor though.
There are free software command line utilities, unar and lsar, that can read .rar files (including RAR5!). They were originally programmed for the macOS app The Unarchiver, but for instance, GNOME’s File Roller will also make use of them. https://theunarchiver.com/command-line