Jool in Ubuntu (20.04+)

At time of writing, this installs Jool 4.0.7:

sudo apt install jool-dkms jool-tools

It’s always a bit outdated. If you prefer a newer version, consider using the standalone Debian packages instead. You can also compile from source.

Whichever method you chose, if you installed via apt, you can uninstall as usual:

sudo apt remove jool-dkms jool-tools