Thonny and MicroPython
Thonny 2.1 had a plug-in called thonny-microbit, which added possibility to program BBC micro:bit.
Thonny 2.2 has plug-ins which add more general support for various MicroPython devices – see https://bitbucket.org/plas/thonny-micropython for more info.
NB! You need at least Thonny 2.2b3 to test it!