[jeroenhd]

dpkg -i ./some-package.deb works just fine, though if that package has dependencies you have to install them first. The same is true for any program on Windows requiring a specific MS VC++ runtime version, you'll have to get those installed manually if they're not built into the package you're trying to install.

apt-cdrom (https://linux.die.net/man/8/apt-cdrom) exists to solve the dependency problem. You can also use the GUI (insert DVD, go to "software & updates", click "add volume"). If you don't use CDs or DVDs for removeable media, you can manually add the repository directory (`deb [trusted=yes] file:/path/to/your/folder ./`) as well.

You can even apt install software like you would with an internet connected device if you have the offline repository in the same place. Redhat's RPM files should work very similarly.

Most of the time, developers don't distribute raw packages the same way Mac and Windows software is distributed. You can download individual packages from your repository of choice and install them on any machine you like (except for maybe Snap, but there's a reason people hate Snap). The difference is that you're not expected to hunt down every download page to get the latest copy of your software.

Annoyingly, the .deb distributions of Discord and VS Code use .deb files instead of repositories to update themselves. This leads to a very annoying Windows-like "click here to download the update" program flow. Luckily, Flatpak versions are available that handle this for stuff you.