In this piece titled Platforms Joel Spolsky says "If you want a platform to be successful, you need massive adoption, and that means you need developers to develop for it. The best way to kill a platform is to make it hard for developers to build on it. Most of the time, this happens because platform companies either don’t know that they have a platform (they think it’s an application) or they get greedy (they want all the revenue for themselves.)"
95% of the time the reason platforms die is that the companies get greedy. When you’re building a platform business, you’re creating an economy around your product. You cannot make the price to participate in that economy a barrier to entry. Most of the value you can charge for your platform is directly related to the number of participants in your economy.
Building a platform economy is a textbook example of the virtuous circle at work. Adoption brings innovation followed by refinement and renewed adoption. Make the barriers low enough initially, and the economy around your platform can expand rapidly — think Linux and Windows. If the barriers are too high, then you’re doomed to be OS/2.
There’s an interesting example of this behaviour playing out in the market right now. The incumbent RTOS vendors, like Wind River, have established numerous barriers to entry to participate in their ecosystems. Green Hills, Microsoft and others (not to mention Linux) are making huge headway by pricing tools and runtimes very very low or making them free. My bet is on the newcomers.