Most important new features:
- Ability to translate UI (see https://github.com/thonny/thonny/blob/master/docs/translate.md)
- Plotter (see https://github.com/thonny/thonny/blob/master/thonny/plugins/help/plotter.rst)
- Several enhancements in the Shell (see https://github.com/thonny/thonny/blob/master/thonny/plugins/help/shell.rst)
- File browser for MicroPython back-ends
- Ability to edit files directly in MicroPython boards
All changes and updates:
https://github.com/thonny/thonny/blob/master/CHANGELOG.rst#320b2-2019-07-13