The PHP RIA SDK by Adobe (http://code.google.com/p/adobe-php-sdk/) has been updated to include new samples showing how to integrate a PHP backend with applications built using Adobe Flex (http://www.adobe.com/devnet/flex/). The SDK now includes samples that use Weborb for PHP from the Midnight Coders to connect Flex and a PHP backend. The MySQL Flex browser is a new application to the SDK that allows you to browse MySQL databases quickly and easily.
All the code in the SDK is open source. The Flex samples are open source, and the SDK includes the following open source projects: AMFPHP (http://www.amfphp.org/), Weborb for PHP (http://www.themidnightcoders.com/weborb/php/index.htm) from the Midnight Coders and the Flex / Ajax Bridge from Adobe, allowing you to connect your Ajax applications and your Flex applications together.