Hideo Kojima, in a lookback interview on 25 years of Metal Gear on PlayStation's offical blog, has revealed a few enticing entails on his new Fox Engine. In particular, Kojima-san took an international approach to the development of the engine:
In order to develop the Fox Engine, I had to understand how things worked elsewhere, so for a year and a half I visited studios around the world, and since we are Japanese people we were able to see the way others worked and recognize that in many respects their methods were better than ours.Since the Fox Engine was going to take a lot of time to create, at the same time we began working on Peace Walker.
While Kojima was slightly dejected about how long it has taken for him to implement the engine, it will be revealed in a little over a month:
The Fox Engine is nearly finished, but the only way to be sure it works is to create a game at the same time and improve the engine with our tools as we go along. Originally we were going to do this for Metal Gear Rising: Revengeance, but a lot happened along the way and instead it is being made with the engine they have at Platinum Games.Production studios in Japan are nearly extinct, a fact that we have recognized for nearly 10 years, and although the Fox Engine is not finished we are ready to show what it can do… on August 30th in Japan to be more specific.
We can only hope that Kojima will be unleashing the power of the Fox engine in some kind of Metal Gear trailer. Either way, it will show what it's capable of and how the Metal Gear franchise may be shaped.
[Source]