Symbian put the emphasis on developers at its annual Smartphone Show in London today, as the company prepares the ground for the Symbian Foundation and the transition of its operating system to an open source platform.

Speaking at the show, Symbian executive vice president of research David Wood said that the three most important words for the company now are "developers, developers, developers".

Wood stated that plans to open source the Symbian OS are proceeding according to schedule.

The company announced new developer tools at the show, including the Symbian Analysis Workbench, which shows what is happening inside a handset as an applications runs, ARM's Profiler for Symbian OS, and a version of the Qt application framework for Nokia's S60 platform.

Symbian also disclosed an extra 12 backers of the Symbian Foundation, including ARM, Huawei, InnoPath Software and Red Bend, bringing the total to more than 50.

The Symbian Foundation is still set to begin operations in the first half of 2009, following plans laid down in June this year.

This will see Symbian purchased by Nokia in the fourth quarter of this year, subject to regulatory approvals, after which the Symbian OS code and three main user interfaces will be contributed to the Foundation and made available under a royalty-free licence.

Symbian chief executive Nigel Clifford claimed that the move to a unified platform will speed new handsets to market by taking the cost and effort out of device creation, and make life easier for developers who will have just a single platform to code for.

"Compatibility is incredibly important," he said. "We cannot afford to mess with the existing ecosystem, so we will need to have a big compatibility effort. "

Clifford added that the move to open source Symbian OS will also solve a conundrum for the mobile industry.

"Right now, you can get lots of free code, or code with proven mobile credentials. We are going to create a proposition that does not involve a trade-off," he said.

Also speaking at the show, Motorola's director of business development for software platforms, John Ellis, maintained that the move to an open platform is a "fundamental technology trend".

Ellis predicted that text and voice will "move into the rear-view mirror" as mobile usage moves more towards social media applications in the future.

"It does not matter if you have a smartphone, a PDA or a mobile internet device. What matters is software, applications," he said.

"[Mobiles are] not just about games, ringtones, and screensavers anymore. Customers are asking for 'experiences'."

Ho-Soo Lee executive vice president of mobile solutions at Samsung, demonstrated his company's concept of what some future mobile devices might look like.

Wearable devices resembling a wristwatch with a flexible display could monitor the user's heart rate and body temperature, but still be capable of displaying real-time video content, he said.