I stumbled upon this game while randomly wandering through some other blogs and gaming sites and was immediately intrigued with the idea of it all. Essentially it is the original D&D rules, cleaned up and better organized for modern readers. And let me just say, I love it.
If you grew up playing D&D, I am pretty sure you could sit down right now and play these rules. Though streamlined and cleaned up a bit, these are the rules, classes/races, etc we grew up with. You will immediately recognize them and be able to understand the rules fully. There are a few deviations, such as the rewritten (read: fixed) Armor Class rule, using a well thought out and better functioning system based on the newer 3.0 rules instead of using the oh-so-painful-to-understand THAC0 rules from the original rules. Other than that, it looks like everything else is simply thought out more fully and refined to produce faster play.
What I really like about it, and something I guess I had thought before but never fully realized, was the fact that this system promotes freeform gaming! There are rules covering a few things such as spell casting, combat, healing, and a few others, but for the most part, it is left up to the GM to wing-it. This is wonderful imo because this is exactly how I GMed those original D&D games nearly 25 years ago.
If you are like me and get glossy dreamy eyes when thinking of those awesome D&D games you used to play with your friends when you were in elementary school, you will enjoy this game. Whitebox provides the bare bones of a game, yet in a slick modern format, that is just waiting for you to come and create worlds to play in. I highly recommend this game to anyone, especially if you used to play D&D that came in a box, years and years ago.