Photos: Linux Greenphone unveiled

Trolltech's out-of-the-box user interface is fairly standard, with familiar contacts, calendar, messaging and other icons. However, Nord admitted that it still had a "few flaws" and would not ship with a browser or media player. "We have partners doing this," he explained.

Nord told ZDNet UK that he thought the last five years had seen an unimpressive level of development in terms of mobile applications, but suggested this was changing.

"Most of the phones sold today are so-called feature phones," he said, "but the makers are not inherently software companies. The focus has now shifted more into software, which is a difficult transition for the industry. We believe Linux can help resolve some of these problems — it's a very solid technology, but more impressive is how the community works in a large ecosystem together, so development happens faster."

He said feature phones, rather than top-end smart phones (where Linux already has some presence) would prove to be the biggest growth market for open source as they present the greatest challenge to developers. "They use home-grown operating systems, and with lots of features the software has turned very messy. It gets harder to drive development," he said.