body: I am going to create open-source project for Linux, and i would like to ask you, how is it with licenses and law.
  
  
  For example i will make a project with GPL license and:
  
  
  1. Must i have company, or can i make it as individual?
  2. Must i have sign any agreement with/out lawyer?
  3. Is it enough to post my project into github with source code and just write that is GPL license?
  4. And is 3. is true that let's say that some man (bad man) make open-source with GPL license and if project will be successful that he just change license or close github repository. Is possible to sue that man?
  
  
  Thank you
  
  
  
title: Law and open-source project