I've just signed Mailana up for BizSpark, Microsoft's new initiative to offer free software to startups. It's a great deal, giving Mailana access to copies of Exchange, MS SQL and Windows installs, though I'll still have to pay for Office licenses to develop with Outlook. But why are they being so nice to me?
The Beast of Redmond isn't generally known for its uninterested altruism, but they've always had a strategy of trying to build an ecosystem around their own software. They make it easy for third-party developers to run on their platform, and bet that their investment in support pays off by locking the users of those applications into purchasing the MS foundations.
This might sound like a no-brainer, but Apple takes the opposite approach. Their culture is to fiercely guard the user experience, and third-party extensions are always a threat to that. That's why Safari and most other internal apps have no support for add-ons. This philosophy definitely helps protect the stabilty and robustness of the platform. Even a lot of hardware drivers are supplied by Apple to avoid the common Windows problem of those installs hosing your system.
In this case, Microsoft's immediate objective is to give early-stage tech companies an alternative to the current default of LAMP for their servers. The official launch of Windows on Amazon's EC2 helps here too. In the end, the reason they're being so helpful is that the open source movement has ended up with an even better environment to develop in than the Microsoft world. This looks like the start of an arms race to win startups' business, which can only help the tech world.