Amazon released Lumberyard today. It seems to be Amazon's stab at making a game engine like Unity or Unreal Engine. It has AWS and Twitch integration, which makes it seem initially very attractive for people who want streaming or cloud integration in their games.
But there's a catch, in the form of a clause in their license.
57.4 Operating Restrictions. Without our prior written consent, (a) the Lumberyard Materials (including any permitted modifications and derivatives) may only be run on computer equipment owned and operated by you or your End Users, or on AWS Services, and may not be run on any Alternate Web Service and (b) your Lumberyard Project may not read data from or write data to any Alternate Web Service. “Alternate Web Service” means any non-AWS web service that is similar to or can act as a replacement for the services listed at docs.aws.amazon.com/lumberyard/userguide/alternate-web-services .
TL;DR: You can't use anything that would replace something amazon offers. i.e. if I wanted to use Hitbox integration instead of Twitch integration (which Amazon provides), they would revoke my ability to use Lumberyard.