[dragonwriter]

> What's the best language to write something like this in? Python?

Python (packed with PyInstaller) is a reasonable choice.

If you know a language that supports cross-platform builds, that (all other things being equal, including library support for what you want to do), that might be more convenient for distribution, OTOH, you probably want to test on your supported platforms anyway, so building on each isn't that much additional work.