ABSTRACT
All of the source code and examples are available at the website https://HTML5GameEnginesBook.com/. All the code, graphics, and sound are licensed free for personal and commercial use (MIT and CC-BY-3.0). Impact is proprietary and is not distributed. It may be purchased at https://impactjs.com.
Impact is an HTML5 JavaScript game engine developed by Dominic Szablewski [63]. It is the only proprietary game engine reviewed in this book. Despite its proprietary nature, the engine is delivered in source form so you can modify it. Also, the barrier to entry is (as of this writing) a modest, no-royalty, one-time $99 fee. You get a lot for $99:
