License of Frappe or ERPNext

Hi friends…
How are you.
I want to know what ERPNet licensing or Frappe.
What if I make a fork?
What if I take as a base to build something Frappe and parallel but with a redesign and reengineering?

My partner and I are evaluating now the core functionality of
ERPNext, to measure if it covers the basic needs of a PYME customer here
in Ecuador , and how difficult would be for us to make the required
customizations for things like tax management, accounting printers, electronic billing etc.

will this GPL3 license be consistent in the future?