The MOUSE language, originally designed for 70s and 80s computers with limited memory, can now be run on an Arduino.
The syntax of MOUSE resembles modern esoteric languages, using Reverse Polish notation and processing single letters as specific instructions.
The current version of MOUSE by [Ivan] includes changes to adapt to the modern computing environment and can run on an ATmega328P with minimal memory usage.
Additional features of [Ivan]'s version of MOUSE include support for PS/2 devices, video output, and saving programs to the internal EEPROM.