My understanding was that they don't want to allow executing downloaded code that hasn't gone through the App Store review (such as JavaScript in web pages). I

My understanding was that they don't want to allow executing downloaded code that hasn't gone through the App Store review (such as JavaScript in web pages). I think they allow Lua for scripting in games, though. So, basically, a 3rd party JavaScript engine is not allowed. I guess you could write your own browser engine that doesn't support JavaScript. I guess Flash was not allowed for performance and security reasons (lots of vulnerabilities, right?)