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.
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.
The Symbian platform architecture is divided into different layers:
The Applications Layer consists of application specific UI and engine components. It uses the services provided by Middleware and OS layers.
The Middleware Layer consists of domains which provide services to the application layer; for example, Multimedia, Networking and Location services.
The Operating System (OS) Layer 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.
The Adaptation layer 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.
The Cellular Platform is the device-specific hardware and cellular software that performs the services required by the Symbian platform.
For more information about layers of the Symbian platform and the packages contained within it, see the Package view of the current Symbian Foundation platform.
A layer can have packages from any technology domain. 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 Introduction to Symbian Developer Community.
You can download the Symbian Foundation Application Development Toolkit and Product Development Toolkit from the Symbian Developer Website.