[yesimahuman]

Thanks, I built Jetstrap :)

To answer the parent, Adobe technically does have a competitor in this space, though it's not focused on bootstrap and it's kind of complicated: http://html.adobe.com/edge/reflow/

As someone with a product in this space, I'm confident each of the current offerings listed above will diverge sufficiently in the future, specifically in their target audience. It's still so early though.