Kent Beck made an interesting observation about the limits of open source software on FLOSS Weekly around one hour into the show. These aren’t his exact words, just my summary.
Big companies like IBM will contribute to big open source projects like Apache because doing so is in their economic interest. And hobbyists will write small applications and give them away. But who is going to write medium-sized software, projects big enough to be useful but not important enough to any one company to fund? That’s where commercial software thrives.
Kent Beck attributes this argument to Paul Davis.
Beck also talked about how he tried but couldn’t pay his bills developing open source software. The hosts were a little defensive and pointed out that many people have managed to earn money indirectly from open source software. Beck agreed but said that the indirect approach didn’t work for him. He said that he donates about 10% of his time to open source development (i.e. xUnit) but he makes his money by charging for his products and services.