The Vazlight Music Library (VML) is a creative commons collection of human made music. All tracks are created by me (Vazlight).
I use FL Studio for production/mixing and Audacity to record audio.
Nothing, they're free to use!
They are under CC-BY.
"This license enables reusers to distribute, remix, adapt, and build upon the material in any medium or format, so long as attribution is given to the creator. The license allows for commercial use."
Creative Commons License