Yes, I have just joined the countless hundreds who have started are currently using the “Arduino” platform for learning. I have to say it is the EASIEST microcontroller to use that I have come across.

The Arduino Uno-compatible board has an MCS-51 (often called 8051 instead) instead of the usual ATmega328P/ATmega168. Specifically, [ElectroBoy] uses the AT89S52.