ImpactJS Now Free and Open Source
ImpactJS is now a free and open source HTML5 game engine. This will make it easier for budding game developers to create games for HTML5.
The advantage of using this game engine is that it works on a wide variety of web browsers that are HTML5 capable. This includes Chrome, Firefox Safari, Opera, and Internet Explorer 9.
Impact also has a Weltmeister Level Editor that can be used for creating top-down RPGs and side scrollers. Entities like NPCs or enemies can be loaded into the Level Editor and connect them via logic chains.
More information can be found here.