[riffraff]

I really wish E4X had gotten traction. I wrote a firefox extension using it and it was awesome to do XUL + JS with it.

Years later

  var foo = <foo>{item}</foo>; 

is the new hotness in facebook's JSX.

[lomnakkus]

AFAIUI from the React people E4X had a lot of incidental complexity and extraneous stuff relative to JSX. So there's that.

I'd argue that with ES6, JSX could just reserve the "jsx" prefix for interpolated strings and go with

   jsx`<foo>blah</foo>`

but that's a typical hindsight-is-20/20-thing.

[insin]

This blog post - "JSX: E4X The Good Parts" - covers what's in and out for JSX:

http://blog.vjeux.com/2013/javascript/jsx-e4x-the-good-parts...