How do you generate revenue from developing FOSS? It's

Do proprietary for money
Do FOSS in spare time

if you want money writing software, whether proprietary or foss, get a job or do freelance development, it's very unlikely you will ever make money from a pet project

as far as foss goes, you can sell access to programs outright but very few people do this and it's usually for niche programs, there's a risk people will release the source but then the proprietary analogue is people will provide a crack and you now have to spend time developing shitty drm that will also be cracked, which means the usual way to make money is by selling support

>>59722737
You wanna make money? Go find someone who'll pay you to write code. Whatever kind of code that may be. Some people will even pay you to write FOSS code, about 80% of kernel devs are paid. But the majority of the time the reason they're paying developers is because the code they want written is boring shit that nobody would ever write as a hobby project.

You wanna scratch your own itch or just work on your own pet project? Don't expect to make a living off of it.

>>59722737
RedHat makes money from selling professional support services.

>>59722737
Enterprise. They go by "free software is only free if your time is worth nothing", so they will actually pay for support. After all they have to pay someone to do the work anyway, so they might as well buy the services of the company that makes the software instead of having to deal with hiring and training employees themselves.

>>59722737
Make something people like to use and accept donations.

This is easier said than done, but most medium sized FOSS projects have at least 1 or 2 full time paid devs, mostly through donations.

Big FOSS projects like Linux and GNOME usually get funding through corporate support and funding, so they're basically just a regular company.