Can I create a cross platform application with HTML5?

I have to target Windows, MacOS, iOS and Android. My plan was to create separate applications for each platform.

However, I am now considering making an HTML5 website (that has different presentations based upon the device being used).

I can create a wrapper for each platform. Windows can include a Webkit control, iOS will have Safari, etc...

The wrapper will load the HTML5 pages into the browser and negotiate input/output for persistance. I 开发者_StackOverflow社区can use WebSockets for communication with the outside world (ie. my server).

What am I missing here? What else would be required and what would be the obstacles I would have to overcome?

Best option for making cross platform applications is PhoneGap.

In PhoneGap you write HTML5 and JS code, it provides access of native APIs using JS code and allows you to compile your application and submit to different App stores.

http://www.phonegap.com