GNUplot
Below is the silent installer and uninstaller for GNUplot that will install GNUplot with default settings. To install with customised settings, use the /SAVEINF and then /LOADINF switches on the setup executable.
The GNUplot Windows installer is packaged with InnoSetup and can accept any of the Inno switches described here.
<package id="gnuplot" name="GNUPlot" revision="2" priority="0" reboot="false">
<variable name="version" value="4.6.0" />
<variable name="file_version" value="460" />
<check type="uninstall" condition="exists" path="gnuplot %version%" />
<install cmd='"%software%\gnuplot\gp%file_version%-win32-setup.exe" /VERYSILENT /SUPPRESSMSGBOXES' />
<upgrade include="remove"/>
<upgrade include="install"/>
<remove cmd='"%ProgramFiles(x86)%\gnuplot\unins000.exe" /VERYSILENT /SUPPRESSMSGBOXES' >
<exit code="any" />
</remove>
</package>