Microsoft has supported running PHP, Java and Node.JS within the Azure App Service (which is what used to be called Azure Web Sites) for years. However, it was always based on Windows and IIS. This blog, for example, runs on the Azure App Service using WordPress. The WordPress application code runs within an IIS web site that runs the PHP handler.
Microsoft is now introducing native Linux support for Node.js and PHP stacks. This means that instead of running within a Windows/IIS instance, your web site will now running natively in Linux. This should improve compatibility and allow for folks used to managing Apache the ability to now do so instead of IIS.
Microsoft is also slowly improving its support for MySQL. Today, the only PAAS solution for MySQL is ClearDB and from my experience its quite expensive and restrictive in its pricing structure. This blog started running MySQL using ClearDB and it was cheaper and easier to scale it running a native Linux VM.
Microsoft will now support running MySQL as part of its native Linux Azure App Service. However, it is only in preview and is pretty limited – it doesn’t support scaling across multiple instances and it runs in the same app instance as your web site (as opposed to setting up a separate dedicated MySQL instance). Microsoft is only recommending it for dev/test scenarios and not for production just yet.