Build Your Own Microcontroller Projects is a website by Wichit Sirichote at the Department of Applied Physics, Faculty of Science, King Mongkut’s Institute of Technology Ladkrabang, Bangkok, Thailand. It features a lot of microcontroller kits based on various microprocessors (6502, Z80, etc.) as well as schematics and electronics resources.
Bought to my attention via this 2019 Gift Guide article by IEEE Spectrum.