MobileSiteOS Basic is a simple perl script used to produce xHTML Mobile Profile compliant web pages for mobile devices, while adding 'Google AdSense' ads and/or AdMob ads dynamically (does not rely on JavaScript). If JavaScript is available and the browser is a desktop version, standard Google ads are substituted instead. Pages are output as XML (mime type 'application/xhtml+xml'), UTF-8 encoded text for mobile devices, but fall back to xHTML Transitional for a desktop browser. Templates are simple xHTML pages with common CSS, which are completely editable for any look or content desired. The latest version incorporates Google Checkout (the JavaScript API) into your website, but automatically falls back to Google 'BuyButtons' for JavaScript disabled devices.