ComputerCraft

ComputerCraft is a modification for Minecraft that’s all about computer programming. It allows you to build in-game Computers and Turtle Robots, and write programs for them using the Lua programming language. The addition of programming to Minecraft opens up a wide variety of new possibilities for automation and creativity. If you’ve never programmed before, it also serves as excellent way to learn a real world skill in a fun, familiar environment.

Development for ComputerCraft has ceased, but there is a fork called CC: Tweaked that offers enhanced performance, improved stability, and a wealth of new features.