> Updating GPL code and making the resulting product proprietary is one of the main things the GPL is supposed to prevent. It works perfectly fine if you own t

> Updating GPL code and making the resulting product proprietary is one of the main things the GPL is supposed to prevent. It works perfectly fine if you own the copyright to all your code. You can't relicense somebody else's code of course, but you can relicense your own. So a company that develops something in-house and then slaps the GPL on the public release can change their mind on the license for future releases all they like. It only gets tricky if they accepted external contributions. In which case there's often a contributor agreement, in which the contributor agree the company can relicense the contributed code.