Gpsbabel
GPSBabel is an open source tool which converts waypoints, tracks, and routes between popular GPS receivers and mapping programs. It also has powerful manipulation tools for such data.
It uses the Inno Setup format and so a silent install can be controlled using the standard Inno switches.
<package id="gpsbabel" name="GPS Babel" revision="20110512.3" reboot="false" priority="0">
<check type="uninstall" condition="exists" path="GPSBabel 1.4.2" />
<install cmd='%SOFTWARE%\GIS\gpsbabel\GPSBabel-1.4.2-Setup.exe /sp- /verysilent /norestart /SUPPRESSMSGBOXES /nocancel /loadinf=%SOFTWARE%\GIS\gpsbabel\gpsbabel.inf' />
<upgrade cmd='%COMSPEC% /c if exist "%programfiles%\GPSBabel\unins000.exe" "%programfiles%\GPSBabel\unins000.exe /sp- /verysilent /norestart /SUPPRESSMSGBOXES /nocancel' />
<upgrade cmd='%SOFTWARE%\GIS\gpsbabel\GPSBabel-1.4.2-Setup.exe /sp- /verysilent /norestart /SUPPRESSMSGBOXES /nocancel /loadinf=%SOFTWARE%\GIS\gpsbabel\gpsbabel.inf' />
<remove cmd='"%programfiles%\GPSBabel\unins000.exe" /sp- /verysilent /norestart /SUPPRESSMSGBOXES /nocancel' />
</package>