[AnIdiotOnTheNet]

> It's a good way to support a project

I disagree. GPL/Commercial dual licensing is always a game of perverse incentives. Even if you aren't actively crippling the free part of your product you're incentivised to make it difficult enough to work with or otherwise support that companies will be inclined to pay you to do it.

[mhh__]

Not necessarily - the GPL is a no-go for some companies regardless of the difference in quality between the free and not free.

Remember that it's not free it's about lawyer approval.