How can I change the default output directory path?

By default, InstallBuilder places generated installers in the output directory under the default installation directory (or in InstallBuilder under the Documents folder on Windows Vista.) You can specify an alternate output directory using the property. The following example would save the generated installer inside /nightly-builds/product/installers/:

<project>
   ...
   <outputDirectory>/nightly-builds/product/installers/</outputDirectory>
   ...
</project>