full cross-platform?

hi

A friend of me wants to add libvgm to Mixxx so we can mix VGM music files with this software.

https://mixxx.org/

I have 2 questions so this can be done properly:

• is libvgm full cross-platform (Windows, MacOS , Linux)?

• could you assign a license if you have time? This is really needed or we can't add the library into Mixxx.
  GPL is perfect.

#129

Thanks so much for your work!
Lisa