Open source is fast emerging as an attractive development model for mobile handsets, with Nokia and Google’s respective strategies putting increasing pressure on other players to adopt an open source strategy.

With an open source development methodology capable of reducing operational costs, harnessing innovation and shortening time to market for new devices and services, analysts note that independent software vendors (ISVs) will find it increasingly difficult to keep pace.

Adam Leach, principal analyst at consulting firm Ovum, said that software vendors need to be familiar with open source environments to be able to respond to demands to integrate customers’ solutions into those environments. In addition, OEMs and operators will start to expect similar levels of transparency and collaboration on key areas of interest for them. “As a result, ISVs will need to evolve their business practices to meet these new expectations, in some cases embracing an open source business model,” he said.

Leach’s comments come on the eve of the launch of the first Android phone – based on Google’s open source OS – and also as Nokia sheds light on its roadmap for Symbian.

The G1 Android phone goes on sale in the US on October 22 via T-Mobile USA, which will be the exclusive carrier of the device.

Meanwhile in London on Tuesday, the 2008 Symbian Smartphone Show kicked off, with announcements from Nokia.

As well as expanding the member base of the Symbian Foundation to more than 50 supporters, the Finnish vendor had also ported the Qt application developer framework, purchased as part of the acquisition of Trolltech, to Symbian S60.

At the time of Nokia’s acquisition of Symbian it was already becoming evident that open source mobile platforms – particularly the Open Handset Alliance’s Android and LiMo’s mobile platform – presented potential threats to the leading mobile OS platforms, notably Symbian, Microsoft Windows Mobile and RIM’s BlackBerry.

Ovum’s Leach confirms this, and believes that if a component is strategically important to a software vendor’s product and there is sufficient technology knowledge of the domain within the company, then a direct approach should be considered by getting involved with the open source project and contributing to its ongoing development.

Leach warns that ISVs need to evaluate new ways of generating income, and notes that adopting an open source licence for product development in a company that does not derive its main revenues from software royalty involves less risk. “Google, for example, make its money through advertising, not selling software; Sun Microsystems makes most of its money through selling servers, not software; equally, Nokia’s business is based on hardware sales. So open sourcing products for these companies poses fewer issues and does not require completely re-engineering their businesses.”

For a pure software vendor however, the move towards a complete open source strategy is riskier, but is not a closed door. Companies could consider professional and value added services; high value features which can be accessed at a premium; and licence protection, under which the software vendor could develop a version of the product under a copyleft licence, benefiting from the open source development methodology but also make available an alternative version under a proprietary licence.

With industry analyst Canalys recently estimating that smartphones represented 13 per cent of all mobile phone shipments during the second quarter, there’s a lot to play for. And while Nokia remained the market leader by some margin with 71 per cent market share, its closest rivals posted higher than average year on year growth. Second-placed RIM closed the market share gap by several points with a total of 7 per cent, while Windows Mobile proponent HTC, and Linux fans Motorola and Samsung more than doubled their shipments with 7 per cent, 3 per cent and 3 per cent respectively. No sign yet of Apple. But it remains to be seen whether the closed platforms can steal any more market share from Symbian, or whether they will find themselves struggling against a tide that is turning in favour of open source.