The root README has the timeline of all generations since 2009. Each generation folder explains its hardware and what is in it. .gitattributes turns off line-ending conversion so all files stay as they were.
Math (IK, rotation), planning, research papers, concept images, the Arduino Mega + SSC-32 notes and the two 2011 Windows programs. From Hexapod-Archief documentation/ (files only; its history stays in the archived repo).