Gitbook (powering the documentation in this link) is also using Slate but they Forked it.
Here is why https://github.com/GitbookIO/slate/blob/master/Readme.md
All slate repos @ https://github.com/GitbookIO?utf8=&q=slate&type=&language=
Here is why https://github.com/GitbookIO/slate/blob/master/Readme.md
All slate repos @ https://github.com/GitbookIO?utf8=&q=slate&type=&language=
> Our goal is not to replace Slate with our fork within the community. We do not expect people to use our fork. If you do, you should know that we will not accept contributions that are not fully aligned with our goals.
This is how the Lucid Emacs situation should have been handled!