Thank you for this tool! We are using it for verification of gerber output before sending any data to the board-house. Gerbv is our last line of defense against engineering mistakes! And it really works great!
Connecting to feature request "Read zipped archives as set of gerbers - ID: 1964898", we are delivering gerber files in ZIP format to the board-house. It would be very handy to have an "export -> Selected layers to ZIP" menu. This would automatically pack the selected layers into a single ZIP file, with original filenames of layers.
This can be done in a file manager as well, however this feature would give the advantage of making sure, only the needed files are in the ZIP file that is sent to the board-house.
A set of 21 patches from 2009 to implement zip file handling.