to open source within two years of the Foundation's announcement.
See www.symbianfoundation.org for more information.
There have been many operating systems available over the last
decade - so what is it about Symbian OS that has enabled it to stay so far
ahead of the competition? The design of Symbian OS is highly modular,
which means that it is constructed from well-defined, discrete parts. Most
Symbian OS components expose a Symbian C++ API 7 and a large number
of these APIs are available to third-party application developers.
At a high level, Symbian OS can be thought of as a layered model, with
a flexible architecture that allows different UI layers to run as platforms
on top of the core operating system. That is, Symbian OS provides a
framework that supplies a common core to enable custom components
to be developed on top of it. The generic UI framework of Symbian
OS supplies the common behavior of the UI and supports extension
by licensees who define their own look and feel. For example, the S60
platform, supplied by Nokia, sits on top of Symbian OS. S60 is the world's
most popular smartphone platform, and is currently used by Nokia, LG
and Samsung. Almost 180million S60 devices had been shipped by S60
licensees by the end of June 2008. 8
The power and configurable design of Symbian OS are the key con-
tributing factors to its success. Today, Symbian OS devices are being
sold in every market segment as you can see from the variety of
hardware shown in Figure 1.3. If you want to find out more about
Symbian and Symbian OS, there are a range of resources including topics
from Symbian Press, available from developer.symbian.com/books ,and
www.forum.nokia.com . If you are new to Symbian OS and interested in
a slightly more detailed overview about Symbian OS, a recommended
resource is the first chapter of [Babin 2007]. 9
Figure 1.3 Symbian OS is everywhere
7 Symbian C++ is a dialect of C++ with idiomatic extensions.
9 The chapter can be downloaded from developer.symbian.com/main/documentation/
books/books files/dasos .