Jeff Atwood wrote a great blog post about why Microsoft can’t use open source in their products. Jon Galloway wrote a complementary post providing some specifics from a Microsoft insider explaining why Microsoft can’t use open source. One of Jon’s salient points is as follows:

Let’s say Microsoft took my advice and shipped Paint.NET as a Windows Vista Ultimate Extra. Unbeknownst to Microsoft – or even the Paint.NET project leads – a project contributor had copied some GPL code and included it in a patch submission (either out of ignorance or as with malice aforethought). Two years later, a competitor runs a binary scan for GPL code and serves Microsoft with a lawsuit for copyright infringement. Microsoft is forced to pay eleventy bajillion dollars and damages. Perhaps even worse, they’re hit with an injunction which prevents selling the offending application, which requires recalling shrinkwrapped boxes and working with computer vendors who’ve got the software pre-installed on computers in their inventory. All for shipping a simple paint program.

This “nightmare scenario,” as Jon calls it, is more real than you might think. In my various roles as a Microsoft contractor and Wintellect cofounder, I have been involved, directly or indirectly, in a handful of lawsuits lodged against Microsoft over the years. And some of them have blown my mind. A few years ago, Wintellect took on the expert witness role when a gentleman sued Microsoft claiming that he invented Minesweeper and Microsoft stole it from him. The plaintiff wanted a royalty for every copy of Windows ever sold with Minesweeper! You can imagine how this went over with the brass at Microsoft.

Developers at Microsoft often joke that Microsoft has more attorneys than developers, or that “there’s an attorney for every programmer.” It’s not quite true, but it sometimes seem as if it is. I personally know of three groups at Microsoft that wanted to use controls from the AJAX Control Toolkit in their projects and were told by Legal that they couldn’t since the Toolkit is now open-source and contains code not written by Microsoft. Is Legal just being stodgy? Not given the long history of frivolous lawsuits filed against Microsoft by people hoping Microsoft will throw them some cash to go away. That’s one attribute of Bill Gates that I’ve always admired: when he thinks he’s right, he’d rather spend a million dollars defending his position than one dollar in hush money.

It would be nice if Microsoft could use open source. But given today’s legal climate, there’s no way that they–or any other company that sells software–can afford to.