You can look at the code, and you can learn from the code. However, you may not copy from the code or use any of the code for other projects. You may not recompile or redistribute modified code. No modifications of source code may be made unless for personal use or to be contributed back to HarryPotterSpells. The only exception to this is everything in the com.hpspells.core.utils.nbt package. The contents of that package are licensed under GPL v3. More information can be found here: http://www.tldrlegal.com/license/gnu-general-public-license-v3-(gpl-3)