The future of the Android OS might look rosy, but how well it performs in the future will depend on how Google and handset manufacturers deal with the problem of fragmentation.

Around 300,000 Android handsets are being activated every day, according to Google's CEO Eric Schmidt. It is also now the fastest-growing mobile OS in the US, according to figures from comScore released earlier this month.

However, a growing number of developers are said to be frustrated by Android. The problem, according to one developer, is the fragmentation of Android-based devices, with several different versions of the operating system being used at any one time.

"The growth in Android has come from a large number of mobile manufacturers finding it easy to adapt to various screen sizes, hardware features and unique user interfaces. This in itself causes fragmentation, with developers having to test across many devices and sometimes create device specific versions," said Ben Trewhella, CTO of Mubaloo, a development firm.

Google licenses Android for free to device manufacturers, which then customize the OS to their liking. Consequently OS updates are often slow to arrive, leaving many users disgruntled. Only Google's own Nexus One and Nexus S devices usually receive the latest OS updates within days.

"Once a handset has been sold, the device manufacturer has little incentive to update their customised Android interface. This inevitably results in most Android users being left with an outdated version of Google's mobile operating system," said Trewhella.

"This fragmentation is also an issue for developers, who may not have the different skillsets or time to develop for anything other than a single platform: most typically the iPhone, which has little or no fragmentation," he continued.

Android's problems with fragmentation are well documented - last month, Macworld reported that Android 2.3 (Honeycomb) was only running on 0.4 percent of Android handsets. In comparison, Android 2.2 was on 51.8 percent on devices running the OS, and 35.2 percent of devices still run Android 2.1.

Compare this to figures for iOS, where around 90 percent are reckoned to be using iOS 4.X, according to figures from Bump Technologies.

However, if rumours about an iPhone nano are true, developers could face a similar problem with fragmentation, as Macworld reported this week.