Mike Potter has posted an update on the status that Adobe is making for developers, including some new offerings for PHPers.
Over the last several months, Adobe has made enormous progress with software developers. In the few short months since the Macromedia acquisition, we have released new products, opened access to SDKs and continued to create communities of open source software.
We released two RIA SDKs: one for PHP developers and one for Ruby on Rails developers. Both of those are free, as in speech. Head to Google Code for the PHP RIA SDK by Adobe or the Ruby on Rails RIA SDK by Adobe. Join the mailing list for either of them (PHP, Ruby), they're fairly active.
It's great to see a larger company taking such an interest in the dynamic web languages out there and providing good, solid tools for thier developers to use to create bigger and better applications.