GPL software is still open source. The problem is when you contribute to a private company's MIT or Apache licensed software.
I would change that to:
'do not contribute to permissively licensed projects. Find a copylefted project and contribute to that.'
Give money and time to causes you support. Go contribute to the BSDs. Volunteer at your local animal shelter. But don't think that you're going to get rich from it. You'll save some puppies and help some people (and maybe some megacorps) but that's all you can expect.
This is Traefik in a nutshell. 1.x had built in support for sharing Lets Encrypt certificates among HA nodes. Once they decided to make a company out of the project 2.x was released which axed the feature as being "too hard to implement." Yet somehow it exists just fine in Traefik Enterprise ($5,000/node).
GPL or its stronger copyleft counterpart, AGPL, can be later closed source too, afaik, at least under two scenarios:
1. Original developer owns all copyrights (CLAs).
2. There's no other contributor but the original developer.
MPLv2 and EPLv2 resist close sourcing the already open sourced bits to the same extent as xGPL, except xGPL is intrusively more viral than these two.
Also, I read somewhere that GPL lets one impose strange restrictions:
1. A vendor distributes binary of GPLd code to "X" (among other non GPLd things), and can impose upon "X" that if "X" does share vendor's GPL code without approval, "X" would breach contract (not necessarily of GPLd code, but of other non-GPLd things).
2. A vendor "rents" / "lends" binaries to "X", in which case the vendor doesn't have to share the binary's GPLd code.
IANAL.
Edit: Clarification. Ref: https://opensource.stackexchange.com/questions/2338/can-i-us...
2. A vendor can "rent" / "lend" a binary to "X", in which case the vendor wouldn't have to share the code.
I'm pretty sure neither of those are legal. https://www.gnu.org/licenses/gpl-faq.en.html#DoesTheGPLAllow...
However, if you have the rights to dual-license the code, either of those would be just fine under whatever second license you'd like to cook up.
Obviously the company policy is "We just sell stuff, leave us alone.". That's why they "invest millions" in patches which are not yet ready for upstream.
[0] https://forum.netgate.com/topic/121969/where-is-the-pfsense-...
AGPL3, but your point stands ;-)
This happens So. Freaking. Often. Companies take open source software private All The Damn Time. They hire the key devs away with just enough money. Then they release another version under a different license. And before you know it a previously open source project is now all but closed source.
It doesn't even have to be with shenanigans this nefarious. Once you have the two or three devs all you have to do is release a value-added component and all but cripple the community one. It's roughly a million times cheaper than an acquisition.
If you want your hard-earned contributions to avoid this fate, do not contribute to "open source" projects. Find a copylefted project and contribute to that. Otherwise your work will end up being coopted by a profit-seeking enterprise.
Open source is the domain of large companies building fiefdoms. Just look at all those Apache projects and who contributes to them and who they're for. You would have to pay me big bucks to contribute to that ecosystem.
GPL or bust.