QUUB is an open-source, micro controller system based on a Raspberry Pi Pico core processor, addressable daughter boards which in turn can have addressable daughter boards, and remote IO modules. It is a general-purpose embedded microprocessor system, the form factor is based on a main MCU board and multiple stacked IO boards called "stackables" plus smaller solder-on boards called "dockables".

This concept of up to 15 addressable stacked boards and 66 addressable smaller boards makes for a very versatile system that can be configured for just about any imaginable application.

The target audience for the QUUB is more the serious hobbyist and low-end BMAC (Building Monitoring and Control) applications, it's way overkill for a beginner's flashing-LED project, although that can can be done as well.