[MichaelGG]

There's a lot of development and apps that simply are not going to have any real difference based on their choice of ORM or even DB. Having it all-in-one has a lot of benefits.

Also, it's unfair to say open source isn't the same. How many PHP projects fairly evaluated anything but MySQL or PHP's built-in MySQL data access libs? And why would you? If you aren't at the point where you need to evaluate, your app will probably work fine on MySQL anyways. Also, Ruby-on-Rails provides quite a bit of defaults...

Microsoft might provide more kinds of libraries, but that's only because of their size. If Zend created an MVC system and built it into PHP, what kind of uptake would that see?