ZeroTier reverts to Apache after 4 years, and there’s a GPL version from 2019.
So, older versions are indeed open source, and new versions will eventually be so as well.
What’s your objection to the BSL? It seems like a great way to provide ongoing funding to open source, and guarantees popular commercially developed software won’t end up as abandonware.
There are several problems with it. The license prevents me from paying some one other than ZeroTier Inc. from hosting it for me, and providing related services. This is a business risk because ZeroTier Inc may have diverging business needs from me. THey may even go bankrupt or be bought out by some one who abandons the product. This would mean I would have to host it myself (Until the version I need becomes Open Source), and I may not want to do that.
It also makes it hard for a fork to develop traction, as a fork would have to start at a much older version that is Open Source, or the ecosystem would have to forgo the opportunity for third-party hosting services to support it.
The freedom to fork is an essential freedom. Without it, I would not feel comfortable contributing to the project. Nor would I feel comfortable basing critical business infrastructure on it.
Others may be fine with proprietary source-available software, and that is fine for them, but I strongly prefer Open Source for my needs, especially for core infrastructure.
I looked at it also but for me the concern was that all access management and configuration is done via their cloud. So they can easily add nodes to my VPN. This is an absolute dealbreaker for me.
I know I can self-host even that top management layer (I think they called it "earth" or something). but they make that pretty complicated, probably on purpose.
In the end I just wrote it off in the end as something that has goals not aligned with mine. I'm going to look at Nebula (from Slack) soon. I use tinc at the moment but I wish it was more performant.
There's many options in this arena now so there's no point in sticking with something that doesn't completely fit your needs.
The concern is the same as that with any other software license that restricts the freedoms of the world to build upon, adapt, and use the software for any purpose.
I'm not some free software zealot; I use macOS and the Creative Cloud and a bunch of other proprietary crap on a daily basis. I just don't pretend it respects my freedom. Nonfree licenses are like that.
It's not like it "switches to even more free": it is presently nonfree.
> It's not like it "switches to even more free": it is presently nonfree.
It's free for any use-case I'm concerned with. I can modify the source, self-host it, and run thousands of nodes through it if I want. All I can't do is take their work, slap my name on it, and sell it.
If that was your intent then VPNCloud is even less free. The GPL3 license means you could never host a closed-source version.