Apple collector and podcaster Stephen Hackett announced a new project today aimed at documenting the long evolution of macOS software design.

The Aqua Screenshot Library is a meticulously compiled database of over 1,500 images cataloging every major release of macOS since September 2000’s Public Beta. Hackett explains that he captured screenshots of major features and applications across each version running on actual period-correct hardware, not virtual machines:

Beyond providing a comprehensive visual reference guide to the Mac’s operating system, the library offers a birds-eye view of design trends over the years (who could forget OS X Lion’s leather-themed iCal?) and a fun look at the changing styles of specific user interface elements.

Check out the full gallery for a trip down memory lane, and keep the page bookmarked, as Hackett promises regular updates for future versions of macOS.