Yep. Clean room reverse engineering also steers clear of copyright, and hardware design cases are very difficult to prove unless it&#x27;s a direct knockoff -- if copyright worked that way, then things like 3rd party auto parts manufacturing couldn&#x27;t exist either.<p>3d sintering is different because as you said, sintering is patented. Physical products have a bunch of rules that are significantly different from software products, and the area is really murky. I don&#x27;t know of any GPL hardware cases, but would doubt they&#x27;d get very far unless you were able to show direct infringement, which is a lot harder.