The <ahref="licenses/mit">MIT License</a> is a permissive license that is short and to the point. It lets people do anything they want with your code as long as they provide attribution back to you and don’t hold you liable.
The <ahref="licenses/apache/">Apache License</a> is a permissive license similar to the MIT License, but also provides an express grant of patent rights from contributors to users.
The GPL (<ahref="licenses/gpl-v2">V2</a> or <ahref="licenses/gpl-v3">V3</a>) is a copyleft license that requires others who modify your code to disclose their changes if they redistribute it in source or binary form. V3 is similar to V2, but adds a restriction restricting use in hardware that forbids software alterations.