IDEs and SDKs were developed and then released for free, and app development for Symbian picked up.

Symbian was intended to be developed by a community led by the Symbian Foundation, which was first announced in June 2008 and which officially launched in April 2009.

Its objective was to publish the source code for the entire Symbian platform under the OSI- and FSF-approved Eclipse Public License (EPL).

UIQ was another Symbian user interface mostly used by Motorola and Sony Ericsson, whereas in Japan there was also the MOAP platform. The non-profit Symbian Foundation was then created to make a royalty-free successor to Symbian OS - seeking to unify the platform, S60 became the Foundation's favoured UI and UIQ stopped development.

Applications of these interfaces were not compatible with each other, despite each being built atop Symbian OS. Symbian^1 (or S60 5th Edition) was created as a result in 2009.

Research in June 2011 indicated that over 39% of mobile developers using Symbian at the time of publication were planning to abandon the platform.

On 22 June 2011, Nokia made an agreement with Accenture for an outsourcing program.

The platform was designated as the successor to Symbian OS, following the official launch of the Symbian Foundation in April 2009.

The Symbian platform was officially made available as open source code in February 2010.

Symbian^3 received the Anna and Belle updates in 2011.

In February 2011, Nokia, by now the only remaining company still supporting Symbian outside Japan, announced that it would use Microsoft's Windows Phone 7 as its primary smartphone platform, whilst Symbian would be gradually wound down.

Symbian OS was a descendant of Psion's EPOC, and runs exclusively on ARM processors, although an unreleased x86 port existed.