Interesting project ! However , could you make the mouse scroll wheel zoom instead of panning ? Panning works by holding the wheelmiddleright button down already but zooming requires an extra action completely unintuitive . Another thing to support would be gerbers . Importing Eagle and KICAD files is nice , but not everyone uses those . And sometimes even with these it is more relevant to review the final files that will go to the fab instead of something generated from the board files . E . g . tracesvias breaking silkscreen could be not visible except from the gerbers . Finally , adding an option to hide the copper fillsrender them as outline only aka KICAD would be very helpful when reviewing boards . Right now it is impossible to see how the traces are stacked on the different layers , because the fills mask them . That can be important for checking things like cross talk , following nets during review , etc .