Espruino Pico is a tiny microcontroller board that runs JavaScript (it doesn’t need to be plugged into a computer), making it easier than ever to control electronics in the real world. You can program it with nothing but a serial terminal program, but there’s also an IDE that runs in the Chrome Web browser. It’s got a syntax highlighted editor as well as a graphical programming language.
Once you have uploaded code, you can inspect and change variables (including functions) while your program is running. If you make something with an Espruino Pico and need to change it a year later, your original code is still there waiting for you!
This is the pinned version of the board, which fits perfectly into breadboard. Also available without pins.