Well, there is an interesting question

Working with PHP is just some of the stuff we do at the OSTC. But it seems that the PHP work is getting more exposure.
The OSTC (previously called the Open Source Software Lab) actually has been around for about 3 years. And for the last 2 1/2 or so years we have really started participating in a more direct way with Open Source.
Today for example we are platinum sponsors for the ASF.
But more concretely we invited the Mozilla foundation to come up to Redmond for a few days just before Vista was released to work with them on what Vista would bring. We did the same thing a year and a half ago with the Apache Software Foundation for Server 2008.
You also might be surprised to know that we have been working very closely with the Samba community. We host several machines in our labs that are used directly by the Samba community for interop testing. And I have an engineer on staff who ensures Samba is tested against 2003/2008/ 2008 R2/Vista and Windows 7.
But what is Microsoft expecting to gain from working with Open Source and Open Source Projects?
I can give you a long flowery answer that marketing would be excited about. But really what it comes down to is that the OSTC's mission is to Make Windows The Best choice Platform for Open Source
Communities
Development
Deployment
The approach we are taking at the OSTC is one of collaboration. We do not go to communities and say this is what we bring and need. Instead we go to communities and ask what can we do to assist in making your project run better on Windows.
And that has really been the genesis of our work in PHP. Making PHP on Windows the best PHP experience anywhere. And that work really has started with PHP 5.3. But more about that in a next post from me.
Our customers are asking for a better heterogeneous systems environment, and it helps the OS community to reach different customers.
Thanks,
Hank.