Enaml-web is like react's JSX, just it uses enaml (a superset of python).
Components are defined declaratively making them easy to read, extend, and modify. It's like using raw html with the addition of variables and programming constructs like conditional and loop statements.
This this translates into a fast and smooth user experience for mobile clients.
Since It's just generating regular HTML, you can integrate any css framework you like, any js libraries you like, and it just works.
I've been told enaml-web is being used at a fortune 500 company and know of several startups that have built applications with it.
For a glance at what it can do checkout this blog post. This site is built with enaml-web.
If you're using it commerically please consider making a donation. Thank you!