Heroku, the "pure platform-as-a-service" provider aimed at developers that over time has added support for languages like Java and Node.js, has just announced support for one of the most widely used -- and widely debated -- languages across the Web: PHP.
Perhaps it was inevitable. The sheer size of the PHP programmer and application base makes it hard for any PaaS to withhold support for it, and in fact all the other major PaaS providers -- Google App Engine, Amazon Elastic Beanstalk, and Windows Azure -- have PHP runtime support.