From the 'yeah, Microsoft does release open source code' files:

Microsoft has been getting cozy with PHP for the last few years and is now getting expanding the relationship. Today Microsoft announced a new open source Software Developer Kit (SDK) for PHP on Microsoft's  cloud services platform Windows Azure.

The idea is to make it easier for PHP developer to hook into Azure. Microsoft is also aiming to make it easier for PHP developers to work with Silverlight and IE 8 with code samples and tools.

PHP for Silverlight is a code sample and tutorial on Microsoft' codeplex site which explains and gives examples of how to integrate Silverlight controls in PHP.

For IE 8 the PHP integration is specifically for the Web Slices and Accelerators feature which pull up specific element of content from a site.

"The overall goal of this project is to demonstrate how PHP applications can take advantage of Microsoft technologies," Microsoft states. "Internet Explorer 8 introduces web slices and accelerators. Because they are based on HTML and XML they can be easily integrated into any web platform."

These new announcements and tools are not about Microsoft getting into open source. Rather from my point of view it's more about open source developers using Microsoft platforms and technology. Microsoft wants to be a platform play for all types of programming languages -- PHP being one of them.

Microsoft tools and sample for PHP are good things for PHP developers, as they provide options and choices for deployment. It also means that Microsoft isn't forcing anyone to specifically use .NET or Microsoft development languages to engage with IE 8, Silverlight or Azure.