Can mobile web apps access the os native environment?

Is it possible for a mobile web app to access and interact with the native mobile OS environment? For example lets say I am creating a mobile web dialer app for some reason.. can the web dialer app be able to pull up my current contacts on my phone or be able to add a new contacts? Or be able to pull up your text msgs/pictures/phone version/type of service/etc.

Since mobile web a开发者_StackOverflowpplications are multi-platform its understandable that each platform would have its pros and cons for the capability that I am asking for so lets just say what about the iPhone and Android platform?

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Not sure if it's what you looking for but PhoneGap (http://www.phonegap.com/) enables html pages to access the mobile OS APIs.

You still need to package and distribute you app through tha app store though.

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Depends on the device you're running on. For example, iPhone's are sandboxed for security reasons so it's highly unlikely that you'll be able to access other parts of the OS. Android on the other since it's open source and more free, might be a different story. It all comes down to what OS you're talking about.