Space-pen is being deprecated. The core team is moving to some unchosen framework like http://rivetsjs.com/. I have been discussing this with them at https://github.com/atom/atom/issues/4673#issuecomment-67402158.
I feel that simple packages should have a simple way to specify the html like the old space-pen even though any new solution should now support the new custom element idiom in Atom core, other web components, and 2-way bindings. Also I agree there should be no dependency on jQuery.
Therefore I am proposing a space-pen-2. A very preliminary spec is at https://gist.github.com/mark-hahn/3f9ee0ba4945a285fb38.
Comments are welcome…