The Device Atlas is just an OPTION available for developers who want to build websites that will deliver mobile friendly content tailored to specific handheld devices. It is a tool devised to provide the most content/layout targetted user experience.
A ".mobi" website means that IT WILL HAVE mobile accessible content. Dot mobi websites are specifically designed for mobile use from Day 1.
Dot mobi sites can ALSO contain full sized screen pages which can be offered and accessed via the autodetection methods (of which mTLD's Device Atlas is one option) or by using subdirectories and links with a courtesy note explaining that some content will be full sized pages and providing a way for the user to get back to mobile sized content. As an option, one could offer manuallly selectable pages based on general scren sizes - small. medium, and full sized. Or they could just design a .mobi site at a specific screen size in mind, say 165 pixels wide.
But that is still missing the BIG point:
Over the last decade+, almost ALL the websites out there on the internet were designed to fit full sized screens ONLY on PCs and laptops - period. Many existing websites include bloated pages using tables and frames and large graphics and pdf files which do not load quickly or play nicely with many mobile phones. Hence those sites will likely provide a bad user experience.
Even if some software programs like Google's mobilizer can strip out and reorganize the old pages to shoehorn them onto a mobile screen, that does not provide a best case scenario for the mobile user. Only a site designed for mobile use can do that best with the user experience in mind.
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This is another example of the kind of tools and services provided by the DotMobi registry to further the buildout of the mobile web and to help .mobi to become synonymous with the mobile web.
Just like:
http://dev.mobi/ and
http://ready.mobi/
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Now what other domain extension is as purposeful, engaged, and dedicated to providing a good user experience?
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