While it's not something I'd do, I don't think it's unethical (assuming he's not violating the GPL agreement).JuLieN wrote:...I still think that selling a free GPLed open-source engine is highly unethical....
The buyers are not forced to buy. They do so because they want to try out what looks like a quality product. And I'm sure they will happy with their purchase.
It's also not clear but the seller may be adding value to the product - for example by offering support or a guarantee. In this case I don't think he is but potentially you could sell a GPLed product and provide support.
Also the buyer may know about the free version yet prefer to pay a small fee for the product as they think it more likely to be supported and updated in the future (I never use free development components for this very reason).
At the very least the seller is making a quality product more widely available.
So where is the crime? Seems like everyone is happy. It's capitalism at it's best - no coercion anywhere!
Steve