Gerber files are the standard format for PCB manufacturing. They contain all of the information needed to create a PCB, including the layout of the traces, vias, and pads. Online Gerber file editors ...
Someone called Rafal Powierski got in touch about a 3D Gerber file viewer he has written. Now, I cannot vouch for any of it, so do your own due diligence, but the video looks pretty interesting. There ...