That said, writing javascript instead of C/C++, and all the things that come with doing that is the whole point of Espruino. If you want to write C/C++ instead of javascript, why are you using Espruino? There's nothing special about the hardware - it can be programmed with whatever you'd normally use for programming the mcu (what this is depends on which board, and I don't know it off the top of my head) - but this is a sort of silly thing to do, since you pay a large premium on the boards to get official and responsive support for the Espruino interpreter.
Espruino is a JavaScript interpreter for low-power Microcontrollers. This site is both a support community for Espruino and a place to share what you are working on.
That said, writing javascript instead of C/C++, and all the things that come with doing that is the whole point of Espruino. If you want to write C/C++ instead of javascript, why are you using Espruino? There's nothing special about the hardware - it can be programmed with whatever you'd normally use for programming the mcu (what this is depends on which board, and I don't know it off the top of my head) - but this is a sort of silly thing to do, since you pay a large premium on the boards to get official and responsive support for the Espruino interpreter.