E4X browser support
e4x, javascript
Solution
Which browsers support E4X
Firefox and others based on the Mozilla codebase.
why isn't it more widely adopted?
Because it offers little practical functionality not already covered by existing standards such as DOM.
OK, it's simpler to use than DOM, but as the price for that you don't get access to all the features of XML, and the thoroughly idiotic, needless XML literal/template syntax is a security disaster, making it so authors of even completely static htaccess-protected documents have to worry about working around the feature.
As a simpler method for accessing the results of an XMLHttpRequest, JSON totally won. For full-on XML processing, you still need DOM. For easier document handling, there are selectors, XPath and JS libraries that can do it without having to introduce weird new language syntax.
That doesn't leave much of a niche for E4X. TBH I wish it would die. (ETA: it has now pretty much done so.)
Problem
I'm trying to figure this out, but there's not much information. Which browsers support E4X, and why isn't it more widely adopted?