It's a question I've seen pop up every now and then. If you look at the current distribution landscape in any given enterprise today you'll probably see a standardization on one distribution, with a few exceptions here and there. This is mostly due to the need to have ease of management and the same goes for container OSes. If you mix several of them you're adding on "management tax" for the underlying OSes, even if the containers might be managed by a tool on top of it.
Deploying/configuring/managing CoreOS is different than RancherOS which is different than SmartOS, for instance.
I say try a few of them, including the tooling that comes with them, and since the containers look the same and will behave the same on all of them you can easily change your underlying OS (and tooling) in this testing phase. Then try the different tools that can be used on top of them and I'm sure you'll find a mix that works for you :)
I posted a reply on the original post, so I'll add it here as well:
Yes, SmartOS is indeed very interesting and has been around for many years already. They've done some incredible work to get Docker containers to work on their platform. The purpose of the comparison here is to show some of the Linux OSes that are focused on containers (mainly Docker but also others), and it's never gonna be an exhaustive list. SmartOS could've been on the list as another alternative.
You're right, it's a list of the OSes and some of their strengths. I'd rather not get into a container OS war on "which one is better", as I stated at the beginning of the article it always depends on your needs :)
Transfer of IP is not reasonable, as you should still own what you have created.
Granting a perpetual and royalty-free license is very common as can be seen in the Apache Individual Contributor License Agreement: https://www.apache.org/licenses/icla.txt
The Apache ICLA states that you still own the copyright of the software and can do what you want with it, they only license it from you and can then use it for the purposes stated in the agreement. It does require you to mention all the patents that you might infringe on, but only if you are aware of them. Otherwise you're pretty much in the clear.
I wouldn't have signed the document mentioned in the article, I think you made the right move.
I say try a few of them, including the tooling that comes with them, and since the containers look the same and will behave the same on all of them you can easily change your underlying OS (and tooling) in this testing phase. Then try the different tools that can be used on top of them and I'm sure you'll find a mix that works for you :)