This is perfectly valid, selling GPL software is fine if you can find someone to pay for them. Wrapping them up in a nice installer and selling a support packag

This is perfectly valid, selling GPL software is fine if you can find someone to pay for them. Wrapping them up in a nice installer and selling a support package, also A-OK, and a frequently recommended business model. Free software doesn't mean free as in price, it is free as in freedom. Keil is a bit different in that you are also paying for their IDE and debugger and such, which are of course non-Free.