It's used for flashing the BBC micro:bit in both Microsoft MakeCode (https://makecode.microbit.org https://makecode.microbit.org) and the micro:bit Python Edito

It's used for flashing the BBC micro:bit in both Microsoft MakeCode (https://makecode.microbit.org https://makecode.microbit.org) and the micro:bit Python Editor (https://python.microbit.org https://python.microbit.org). MakeCode uses it for lots of other devices like MakeCode Arcade too https://arcade.makecode.com https://arcade.makecode.com ) It's amazing for students to be able to quickly get a program they've written in their browser onto a device in their hands that can respond to and interact with the real world. Also great because with MicroPython and the Python Editor you get a standalone Python environment including REPL that's completely isolated from the PC - schools love it because no matter what the students do they're not going to break the host PCs. (The firmware that implements web USB on the micro:bit's USB interface chip is open source, DAPLink https://github.com/ARMmbed/DAPLink https://github.com/ARMmbed/DAPLink)