A few weeks back, intrepid reporter Will Watts over at RegDeveloper in the UK broke a story about how Microsoft was threatening legal action against a developer for creating a unit testing extension to Visual Studio, known as TestDriven.Net. The story is ironic given that the developer in question, Jamie Cansdale of London, had previously won a Microsoft MVP award for the same product. But what Microsoft is not A few weeks back, intrepid reporter Will Watts over at RegDeveloper in the UK broke a story about how Microsoft was threatening legal action against a developer for creating a unit testing extension to Visual Studio, known as TestDriven.Net. The story is ironic given that the developer in question, Jamie Cansdale of London, had previously won a Microsoft MVP award for the same product. But what Microsoft is not happy about is the fact that Jamie’s extension works with any version of Visual Studio including the free version Visual Studio Express, possibly against the terms of Microsoft’s license. Dan Fernandez, the product manager for Visual Studio Express makes a case for why Jamie should abandon his efforts on the Express edition. And I can understand from Microsoft’s perspective why they would want to limit the extensibility of the Express edition. After all, they don’t make money off it. They want users to have a compelling reason to upgrade to a paid version of Visual Studio and they’d rather point these folks to all the additional features Microsoft has created as well as extensions developed by their partners. What Microsoft wants is that the third party products, whether written by hobbyists or professionals, serve Microsoft’s business model, not their own.Microsoft has always had great developer programs, and even at the CEO level, they get why developers matter. (Can you imagine any CEO other than Steve Ballmer doing his famous sweat-soaked “Developers, developers, developers” chant? If you can, I apologize for the visual.) But I think increasingly, Microsoft is running into the limits of its own model. It’s seeking grassroots support to compete against the growing momentum in open source, and it’s at a disadvantage. If Jamie had written his extension for Eclipse, there wouldn’t be any limitations in what he could do. So where do you think the next generation of Jamie Cansdale’s will focus their efforts? Perhaps this example also illustrates at a fundamental level the difference between the “free” (as in gratis) Express editions and the truly free (as in freedom) of open source software. The Express editions, whether of tools or databases, have been designed with limitations that sooner or later will require some percentage of users to upgrade to a commercial edition. They are in effect, crippleware, and users should understand what they are getting into when they use them. I just wonder what Verity Stob would have to say about all this. I don’t even think she could make something like this up. Open Source