Another Flash Game Engine I Found

This flash based game engine uses action script 3, xml, etc. They provide the core engine as open source (free) and then they offer premium components to add functionality to your game (which you have to pay for). There's going to be an Editor made with flash and a networking premium component for enhanced networking. They provide simple networking already.

The core engine comes with a default game setup so you can start with something and just edit and change until you have what you want. It has 2d physics, sprite or swf-based 2d rendering, tile maps, pathfinding, and flash UI capability... So, out of the box, you can make a nice 2d game with simple networking and physics.
I might reconsider this over Alternativa Platform. Depends which one comes out on top. But it's already open-source, which is always a plus.
The image on the right is an example game made with the engine.