It's really bugging me people are using the word "fork". This is not a fork, it's a competing container format, there isn't any docker code in Rocket AFAIK. Even @shykes called it a fork in a comment, it's not somebody taking your code and doing something different with it, they are doing their own implementation. Ideas aren't "forked", code is.

As to everything else, I manage CoreOS clusters with docker for now, and while this came out of the blue (seems like for Docker folks as well) I'm happy to see what happens as a result. I'm not sure why there are hurt feelings over the announcement, didn't find anything particularly in bad taste and what exactly is wrong with promoting your new product?

The CoreOS team isn't under any obligation to docker to contribute however anyone on the docker team want's them too. Even if these issues have been discussed before they've clearly taken a different path and that's within their right, not sure where mud is being slung. Where this will lead who knows, but hopefully there will still be good collaboration between different groups as they pursue their own goals that align with their needs.

EDIT: I haven't actually looked at the code, so if somebody wants to prove what I'm saying wrong please do. I'm basing what I know off the announcement.