So I just recently started a project very similar to @HaydenM's USB Rubber Ducky Toolkit. I wanted a cross-platform, lightweight emulator that I could easily push onto an otherwise clean target machine, and emulate my ducky script code without having to go through the monotonous process of encoding, transferring the encoded file, placing onto the Ducky, inserting onto the target machine, testing, and repeating. It has not been validated with all kinds of Ducky input, and has not been tested with other localization. It's built on Python3, and uses the PyAutoGUI library for its keystroke emulation. If anyone's interested, the code is at the following Github page:
Source Code: https://github.com/terrabitz/QuackTest/
Executables: https://github.com/terrabitz/QuackTest/releases/tag/v0.1
I have precompiled some executables using PyInstaller. I have precompiled both the CLI and GUI for Linux and Windows. (I haven't gotten it made for Mac, simply because I don't have one to compile on; however, the code should be mostly cross-compatible). Please note, the Windows *win.exe files don't seem to work on all environments, primarily unpatched ones that don't have all the necessary C++ redistributable libraries. I haven't yet been able to figure out why this is, but even on these, the *win.zip versions seem to work OK.
Here's what the GUI version looks like on Windows:
