This has changed in recent years with the huge increase of popularity of the GNU/Linux user will be able to use my software is to release it as source and let them compile it manually.
As a final note, you really shouldn't be scared of such programs.
From the release notes: "Ultimate Edition 5.5 was built from the Ubuntu 17.04 'Zesty Zapus' tree, using a combination of Tmosb (Thee Mahn's Operating System Builder) and work by hand.
I hope this helps a bit; not all distributions use package managers, so if you want to learn more about the "old ways" you can try things like Slackware or Gen Too!
That may tell you more than you'll be comfortable learning are packages with (normally) compiled programs that someone compiled, installed, configured and adapted to a specific operating system.
Someone took care of dependencies, side effects, etc.
Note that format is used by Ubuntu and several other distributions, like debian, Mint, etc...
The program apt-get can get used a frontend for dpkg-source.