Some time back, I was contacted by someone from cadlab.io, asking if I would like to try it out.
Cadlab.io is a way of providing git with a extension to show Cadsoft Eagle files.
As the gif shows, there are ways of comparing the different commits, and showing both PCB layout and schematics.
There is both a free version, and a paid one with private repositories. It’s a great tool for developing hardware, I just wish that github and the like would adopt it and incorporate it into their platform.
From what I have been able to get out of cadlab, KICAD files should be supported by the end of the year, and Altium may come after that. For the record, I’m not receiving anything for writing this, but its appearing as a new, useful tool for making hardware.