Licenses are perpetual. They do not expire and do not need to be renewed.
Licenses can be upgraded. You can upgrade to a more expensive license later paying only the difference in cost.
Pay attention to the distribution type - Hosted (sites / servers), binary (applications) or source (includes all the others).
Choose according to your needs (more below).
All licenses allow commercial use unless otherwise indicated.
Build a line-drawing game such as Flight Control quickly using this full-featured starterkit. Fully commented source-code helps you get a head start and understand how such games are developed.