@Floid
You just reiterated my point, but I think you're wrong about the intent of certain open source licenses. Under the GPL, for example, dynamic linking and internal commercial use are highly contentious issues.
Personally, I prefer a BSD-style license for open source projects, and I do not support software patents. It's unreasonable, unconscionable even, to expect software developers to start every new project from first principles. It's not that extreme, I know, but companies like Microsoft, Apple, and yes, Amiga and Hyperion, would certainly prefer you don't use their operating system products as a foundation for creating competition for their productivity applications. Hell, Microsoft even forbids it in their license agreements. It's not enforceable, of course.