Today, there are at least five different versions of Android on the market. Many of them are highly customized to allow for new features and device differentiation, but that same customization also makes it harder for vendors to update them to the latest versions. New releases and versions of Android are often outdated by newer versions in the span of just a few weeks. For example, the Nexus One when released was capable of running apps like Google Earth that devices such as the Droid could not, because it ran Android 2.0, not 2.1.Tablet vendors complain their Android offerings lack features such as Android Market because Google forbids them to install the marketplace app, forcing them to create proprietary alternatives. It would appear Android is indeed fragmenting -- but perhaps there are other forces at work.