The Adrenaline Vault posted an interview with John Austin of Numerical Design, the team behind the NetImmerse game engine. Here's a sniplet:
Numerical Design focuses just on engine development. Can a company succeed using that business model?
Without a doubt. Through focusing on the engine, in the long term we deliver to developers a better total bundle of features, support, and price. More than two dozen titles in the last year have been released or are in development using NetImmerse. "