I believe this would require agreement from all contributors, or for them to sign some kind of contributor licence agreement.

Interesting excerpt from Steamworks docs:

Which Open Source licenses are compatible with the Steamworks SDK?

In general, permissive licenses that do not put any requirements on you to redistribute your modifications under an open source license work fine. Common permissive and acceptable licenses includes MIT License, BSD 3-clause and 4-clause, Apache 2.0 and WTFPL.

Which Open Source Licenses are problematic for shipping on Steam?

Generally, any license that has a so-called “copyleft” element will be problematic when combining code with the Steamworks SDK. The best-known example is GPL.

But I saw a GPL-licensed application on Steam!

This can happen if the author of the code that is GPL-licensed has given the permission to do so. The author can of course always (a) decide to grant Valve a different license than the author grants everyone else or (b) decide that what the Steamworks SDK does is just a communication with a service that does not invoke the copyleft requirement of the GPL.

Sounds like (b) above could apply to you?

Interesting. So that phrasing sounds like even if you don’t use the steam works SDK then you can’t use GPL. I wonder how Krita reconciled that?

Does your game use the steamworks SDK? If not, then you can publish it on steam as GPL or even AGPL

Yes. But it doesn’t have to replace your default terminal emulator. You can have multiple and use any of them.

I see what you mean. Yes there are great examples like those that offer support contracts for the open source software projects.

I think one point of confusion here is that as open source licenced projects, they do not restrict commercial use. The companies that lead the development just happen to also offer the best paid support.

Minor correction: proxmox is AGPL so free to use commercially without their support contract.

Ubuntu and LibreOffice are both free for commercial use. Or am I misunderstanding what you mean?

It’s no longer open source if you restrict commercial usage. Sure, licence your software that way if you want to, but don’t call it open source.

git clean does. Turns out VSCode did a clean with that GUI option at that time, not sure of current behaviour.