A follow up from “Improving open source hardware: Visual diffs”. Werner writes -

Over at Qi-Hardware, we have a visual revision history for schematics, for KiCad and git. (Doing the same for layouts is still in the queue.)

This is what a simple project looks like:
http://projects.qi-hardware.com/schhist/atusb/

Click on a thumbnail to enlarge. Click again for a PDF with both versions.

The project from which the design comes is here:
http://projects.qi-hardware.com/index.php/p/ben-wpan/source/tree/master/atben/

The scripts that go through the project’s git history, find the differences, and do the highlighting, are here:
http://projects.qi-hardware.com/index.php/p/eda-tools/source/tree/master/schhist

The scrips also follow addition, deletion, and renaming of files. The whole process is kicked off when something new is committed to the repository. Here are a few more projects:
http://projects.qi-hardware.com/schhist/

Visit Qi hardware.