Not really. Way back when, I wanted to hack sleepycat db support into a closed source third party platform that had an extension API. It would have taken a bit

Not really. Way back when, I wanted to hack sleepycat db support into a closed source third party platform that had an extension API. It would have taken a bit of code, and a dll load. Not my application, I didn't have source for it, and I was willing to release my extension as GPL. Sleepycat didn't see it my way and wanted something like 10k/year and a maintenance agreement for the right to do the code and release it a GPL. So, to sum up, the GPL prevented me from writing and releasing GPLd code.