Google previews PHP on App Engine
PHP is the latest addition to the range of languages supported on Google's App Engine. The PaaS (Platform as a Service) already supports Python, Java and Go and, like the languages before it, PHP is being introduced first as a limited preview experimental feature.
The PHP implementation on App Engine currently runs PHP applications using PHP 5.4 in a sandboxed environment which prevents writing to the filesystem, opening sockets or accessing hosts directly or making system calls. Applications must also respond quickly, within a few seconds, to fit in with the App Engine architecture. For storage, PHP applications can use Google Cloud Storage for persistent files, and for access to other hosts, an App Engine URL Fetch API is available for HTTP and HTTPS requests. The service also offers access to the MySQL-5.5-compatible Google Cloud SQL and to many established App Engine APIs including Memcache, Task Queues, Users API and Mail API. There is also support for standard App Engine features for security and web performance.
Users who wish to make use of the App Engine runtime service in the Google cloud will need to register to have their app whitelisted. Development though, can take place offline using the PHP SDK which locally emulates App Engine services. A Getting Started guide works through getting this running and developing App Engine aware applications.