Having signed the NDA I can tell you it says no such thing. It simply says I can't use the various a-eon ip in external products and that I can't talk about what software is going on behind the scenes. It doesn't prevent me from writing my own software (subject to not using the IP ofcourse) and it doesn't prevent me from writing for any OS.
Well, that is good, I guess. How do you distinguish between what is "their IP" and what is "your IP"? Is it about the ideas, the algorithms, or about the source code? Developers should be aware that NDAs are negotiable, it is not just a "sign here" thing.