Tangentially, I had read somewhere some years ago, that the Dropbox GUI clients on some or all of Linux, Windows and macOS were written in Python and wxPython.

Tangentially, I had read somewhere some years ago, that the Dropbox GUI clients on some or all of Linux, Windows and macOS were written in Python and wxPython. The one that you activate from the system tray, in the case of Windows, at least. This may have overlapped with when Guido was working there, though they may have built those clients before he joined, of course.