Windows 10 includes the Windows Subsystem for Linux (WSL), also known as "Bash for Windows". This can be used to run AppImages on Windows.
Microsoft has made it a bit harder than double-clicking a file, though:
- Enable developer mode (hello Microsoft, Linux is not just for developers)
- Install Windows Subsystem for Linux
- Install Xming (or another X Windows Server that runs on Windows) and launch it
sudo apt install libgtk2.0-0 # and possibly some other deps we consider part of each system
chmod a+x /mnt/c/Users/User/Downloads/Leafpad-0.8.18.1.glibc2.4-x86_64.AppImage
/mnt/c/Users/User/Downloads/Leafpad-0.8.18.1.glibc2.4-x86_64.AppImage --appimage-extract since Windows doesn't support FUSE yet (vote on it if you would like to see this change)