A developer named angelthebox has created a Minecraft server called Macerun that runs on the ESP32-S3 microcontroller, using Minecraft version 1.16.5 rewritten in C. Key features include the ability for players to join the server, explore the world, place and break blocks, procedural world chunk generation, basic crafting mechanics with 2x2 recipes, in-game chat, and tracking of basic physics, health, and hunger. Changes to blocks are saved to the chip's flash memory. However, the server lacks mobs, 3x3 crafting recipes, and the ability to retain player inventories and positions after exiting. The source code is available on the Macerun GitHub page.