The key is to write your app from the ground up.

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By building on open Web technologies like HTML5 and Mozilla-proposed APIs, the Mozilla Marketplace will enable developers to write one app that runs across devices and platforms.

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If a third-party developer wants to write a killer-app for Windows 8, they cannot.

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Choosing one's own paper will be a boon for those who love their Moleskine notebooks and personalized journals because anything they write there can be sent back to the iNotebook iPad app.

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With services like App Press or AppBreeder, you can even make your an app for your business without knowing how to write a single line of code.

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If you want, you can slide the app farther to the right, getting you into the Hub to read and write.

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They are now working on adding improvements, like live data web-hooks, which make it possible to write a web app that talks to a sensor without first learning about embedded programming, electronics or networking.

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OpenSocial's greatest strength could be its greatest weakness: Google hopes applications developers will work with OpenSocial technology because they need only write an app once for it to run on many popular sites, including Orkut, MySpace, Friendster and Bebo.

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OpenSocial's greatest strength could be its greatest weakness: Google (nasdaq: GOOG - news - people ) hopes applications developers will work with OpenSocial technology because they need only write an app once for it to run on many popular sites, including Orkut, MySpace, Friendster and Bebo.

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