I wrote a small script a while back that's gained a surprising amount of popularity thanks to a plug from the site that it posts to. [...] I learned that this [connection from the script] could be done with streams, I attempted to implement it in that fashion, but ran into strange issues where I would get 404 or 500-level HTTP errors rather than the response I was expected.

He eventually found the bug related to his problem (in the 5.2.x branch) but happily notes that it has been corrected and will be patched in the upcoming 5.3 (and 6) branches.

PHP-Ext is an open source widget library written for PHP 4 and 5 to empower the UI Layer. It is based on Ext JS javascript widgets which provide a standard and powerful API to build Rich Internet Applications. It basically works as a convenient wrapper for the Ext JS Javascript Objects.

And from the ExtPHP site:

I needed to be the one person who would have to wrestle JavaScript when problems happened. I therefore needed a way to insulate them from the gory details, which is why I created ExtPHP. As you may have guessed from subtle hints, such as this entry's 12-feet tall header, ExtPHP creates a PHP wrapper for ExtJS.

The Ajaxian post also includes code examples for each of them, one showing form construction and the other a tabbed interface.