Does Heroku support PHP? [closed]
Heroku supports PHP de facto. They originally supported PHP for Facebook apps specifically but now host many production PHP sites that are not Facebook apps. (Source -- direct communication with Heroku sales earlier this year.)
There is an official PHP buildpack (see the docs for info on what buildpacks are and how they work).
There are also many unofficial PHP buildpacks that improve on the original. The official PHP buildpack has a single blocking Apache worker and little support for add-ons. It also doesn't use Vulcan to build binaries. See my buildpack, intended for Wordpress or other memory-intensive applications, or my buildpack's parent, the Winglian buildpack.
UPDATE: Heroku now officially supports PHP and provides a drastically improved official buildpack.