Facebook App Devs Get Javascript

It has been an oft-lamented fact of the Facebook Platform thus far in its life that, in order to use all but the most simple of Javascript functionality–the cornerstone of the AJAX technology so loved these days–Facebook app developers have had to host their canvas pages in an iframe, thus foregoing the use of Facebook’s convenient FBML. There has been, in other words, a trade-off between functionality and the ease of designing an app that integrates well with a user’s Facebook experience.