BizSpark - M$ for free

Microsoft offers a program for start-ups that enables them to get a large assortment of Microsoft related technology for free.

Initial eligibility is based on being a privately held firm (you lose status if you go public) and you can stay in the program for three years (you get assessed each year though).

They specifically list more details as well.

An eligible Startup must have the following characteristics at the time of joining:

1. Actively engaged in development of a software-based product or service that will form a core piece of its current or intended business[1]
2. Privately held
3. In business for less than 3 years at the time of enrollment[2]
4. Less than US $1 million in annual revenue [3].

The highlights of what you can get are:

1. All the software included is equivalent to a Microsoft® Visual Studio® Team System Team Suite (VSTS) with MSDN® Premium subscription. Additionally, VSTS Team Foundation Server (Standard Edition) is available for use by the entire development team.
2. Expression® Studio Version 2
3. Production use rights to host a “software-plus-services” solution (developed during participation in the BizSpark Program, on any platform) over the Internet, with regard to the latest versions of Microsoft products including:
4. Microsoft Windows Server® (all editions up to and including Enterprise)
5. Microsoft SQL Server® (all editions)
6. Microsoft Office SharePoint® Portal Server

Here is a link