Custom kernel (Accessory, rare):

• Must be crafted by the owner and cannot be sold, given away, or otherwise transferred. Sometimes explodes during the crafting process, causing unconsciousness and 2d6 damage.
• 10% attack and defense bonuses to weapons and armour that were equipped at the time of crafting, but -10% on new weapons and armour.
• Lightness grants +10 speed.

Switch to a distro lineage whose package manager builds in the necessary facilities? Someone’s already mentioned Nix, and Gentoo has the --fetchonly switch for Portage which will download (but not install) everything required for a specified package including dependencies, so you can copy all of the files to an external drive at once.

Money isn’t important. Some complex software is, in fact, maintained by unpaid volunteers who feel strongly about the project. That doesn’t mean it’s easy (in fact it’s quite difficult to keep the lights on and the code up-to-date), but it is A Thing That Happens despite being difficult.

What is important is the size of the codebase (in the case of a fork, that’s the code either written for the fork or code that the fork preserves and maintains that isn’t in the original anymore), the length of time it’s been actively worked on, and the bus factor. Some would-be browser forks are indeed trivial and ephemeral one-man shows. Others have years of active commit history, carry tens or even hundreds of thousands of lines of novel or preserved code, and have many people working on them.