If you want to gain a better understanding of Symbian OS application development, one way is to study how other applications have been built. One solution for examining Symbian OS Installation (SIS) files is to extract the files contained and install them on a smartphone. Unsis is a Windows-based tool that lets you extract the files within a SIS file using your Windows PC. The Unsis tool can be found at the Symbian website here>>

Unsis requires Perl version 5.6 or higher. The Perl version number can be found with the following command: "perl -v".

Note: To run Unsis you will need to download Perl for Windows, version 5.6 or higher, which can be found at: http://www.activestate.com/Products/ActivePerl/. The Perl version (5.00) currently distributed in Symbian SDK's can't be used.

The Unsis command is invoked as follows:
 $ unsis <SIS file> <output directory>

This will store the contents of the given SIS file in the output directory. For example, if there is a SIS file named "app.sis" in the current working directory, the following command can be given:
 $ unsis app.sis

This will create a directory tree under the current working directory containing the files in the SIS file, for example, a folder "system\apps\app" containing the files "app.aif", "app.app" and "app.rsc".