Not Invented Here?
(Note: this post comes from a debate I was having over on gamedev.net, so the tone is a bit harsher than my usual friendly demeanor. :))
I suggest you read the following article to understand my position:
The conventional wisdom is that it is better to use components off the shelf (COTS). It seems mature, modern, and hip. It is also over generalized.
So license Renderware, license Havok, and so on. Put this altogether and just concentrate on gameplay. Sounds great, right? But what happens when EA comes along and buys up your middleware? What if EA is your main competitor? How good is support going to be at that point?
What if you need a new feature for a totally new game play mechanic, are you going to ask EA to implement this for you? How long will it take? In our game, my turn around time for new features is typically a day or two. My turn around time for support is a 10 second walk across the office.
If physics or graphics are a core feature of your game, it is incredibly risky to out-source this to an external library. That’s why I think many games so far have had limited use of physics, because it is not core, it is out-sourced.