License: http://www.wired.com/images_blogs/gadgetlab/files/iphone-sdk...
Relevant parts (emphasis in italics):
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3.3 Program Requirements for Applications
Any Application developed using this SDK must comply with these criteria and requirements, as they may be modified by Apple from time to time: ....
3.3.2 An Application may not itself install or launch other executable code by any means, including without limitation through the use of a plug-in architecture, calling other frameworks, other APIs or otherwise. No interpreted code may be downloaded and used in an Application except for code that is interpreted and run by Apple's Published APIs and builtin interpreter(s).
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Combine the above with this:
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3.2 Use of the SDK
As a condition to using the SDK, You agree that: (a) You will only use the SDK for the purposes and in the manner expressly permitted by this Agreement and in accordance with all applicable laws and regulations;
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TL;DR (at least how I understood it and IANAL) you can't even legally build any browser which uses its own engine and can run JavaScript code from the network (which is virtually any browser) if you use iOS SDK from Apple.
Of course you can simply ignore this sick level of insanity and build whatever you want, but we are talking about that Apple attempted to legally ban you from building certain applications (it's not even about accepting them in the store, it's about building in compliance with the SDK license!).
Such kind of stuff makes me have zero respect for Apple in general.