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<concept id="GUID-13987218-9427-455E-AC77-ADE6B0E9CD7E" xml:lang="en"><title>Introduction
to Symbian^3</title><shortdesc>The Symbian platform, is a comprehensive open-source software platform
for Symbian-based devices. The platform is used by device manufactures to
build devices, and by third-party developers to create after-market applications
for installation onto devices.</shortdesc><prolog><metadata><keywords/></metadata></prolog><conbody>
<section id="GUID-1212158F-A8CF-41FE-A6B9-4461D90EA2A5"><title>Overview</title><p>The
Symbian platform includes a customizable user interface, a rich set of applications,
common user interface components (AVKON, UIKON) and development tools for
implementing new applications. It also includes tools and documentation that
enables device creators and application developers to create feature-rich
devices and applications.</p><p>The Symbian platform architecture is divided
into different layers:</p><ul>
<li><p>The <b>Applications Layer</b> consists of application specific UI and
engine components. It uses the services provided by Middleware and OS layers. </p></li>
<li><p>The <b>Middleware Layer</b> consists of domains which provide services
to the application layer; for example, Multimedia, Networking and Location
services.</p></li>
<li><p>The <b>Operating System (OS) Layer</b> provides all higher-level
OS services across a full range of technology domains such as communications,
networking, graphics, multimedia and so on. It also includes low-level OS
services such as frameworks, libraries and utilities, which turn the abstracted
hardware and OS mechanisms into a programmable interface. </p></li>
<li><p>The <b>Adaptation layer</b> integrates the generic platform software
with the phone’s cellular platform. It is implemented by the device creators
though reference implementations are provided with the platform.</p><draft-comment time="2009-12-08T14:38" translate="no">Give link to the adaptation documentation.</draft-comment></li>
<li><p>The <b>Cellular Platform</b> is the device-specific hardware and cellular
software that performs the services required by the Symbian platform.</p></li>
</ul><p>For more information about layers of the Symbian platform and the
packages contained within it, see the <xref href="http://developer.symbian.org/downloads/system_models/foundationpkg_22-05-09.svg" scope="external">Package view of the current Symbian Foundation platform</xref>.</p><fig id="GUID-AD79AEF5-1DB3-47F7-9B42-FE5C7FE7C6A3">
<title>Architecture of the Symbian platform</title>
<image href="GUID-6913F58F-FDA1-4708-B03E-16AF6C545E5B_d0e1315_href.jpg" placement="inline"/>
</fig><p>A layer can have packages from any <xref href="http://developer.symbian.org/main/source/technology_domains/index.php.dita">technology
domain</xref>. Technology domains are a group of packages, each of which is
a collection of components. To understand more about the architecture, what
the platform offers, see <xref href="http://developer.symbian.org/wiki/index.php/Main_Page.dita">Introduction
to Symbian Developer Community</xref>.</p></section>
<section id="GUID-6D6715BB-B591-4C97-82BF-1AA68079B45C"><title>Platform UID</title><p>The
platform UID for Symbian^3 is 0x20022E6D.</p></section>
<section id="GUID-177B4AB9-E89E-4AF4-8BC9-503E9F747FE3"><title>Download</title><ul>
<li><p>You can download the Application Development Toolkit and Product Development
Toolkit from the <xref href="http://developer.symbian.org/main/tools_and_kits/index.php" scope="external">Symbian Developer</xref> Website.</p></li>

</ul></section>
</conbody><related-links>
<linklist>
<link href="GUID-6F1ED7D0-5F41-4587-89AA-8DDE7AEC916F.dita"><linktext>What's new
in Symbian^3</linktext></link>
<link href="GUID-AB69D251-7635-4325-BBCE-92F7AFC86DC2.dita"><linktext>New C++ APIs
in Symbian^3</linktext></link>
<link href="GUID-BA0A115B-068C-4257-9489-DF35DF633AD2.dita"><linktext>Porting applications
to Symbian^3</linktext></link>
</linklist>
</related-links></concept>