Definitions:
    the Copyright Owner (hereby CupCakeR - https://www.gmodstore.com/users/76561198106129502)
    the Software (hereby the Library)
    Garry's Mod Marketplace is any online and offline marketplace that sells Garry's Mod game modifications in any way, including, but not limited to Gmodstore.com 

Contents:

You are free to use, redistribute, and modify the Library as long as it is not for commercial usage on any Garry's Mod Marketplace, and the name and license of the Library is not altered in any way.
If it is not for commerical usage on any Garry's Mod Marketplace you are allowed to use it, if you follow the other conditions of this license.

For any commercical usage on a Garry's Mod Marketplace you have to grant CupCakeR 20% of all revenue, unless another percentage have been stated in a legally binding written statement by CupCakeR.