[brightball]

I'm going to take a leap and assume you've done some Rails work because Ember tends to have a lot of Rails users.

In Rails, there's a default view layer handled by ERB but it can be mixed and matched with HAML, Slim or any other view layer. Likewise, you can use ERB, HAML and Slim outside of Rails entirely.

There are frameworks like Meteor that let you have an interchangeable view layer. There are others that build the entire full stack framework around THEIR view layer.

If Meteor made React the default view layer...that would be a step towards unifying the fronts. One full stack system with a shared layer that can be use inside or outside of that particular framework.