Compiling the application
For people who want the very latest source code, it can be downloaded from SourceForge's SVN Browser, or by using an SVN client (such as TortioseSVN) as described here in the SF docs. For SVN experts, it may be enough to say that the URL is https://localupdatepubl.svn.sourceforge.net/svnroot/localupdatepubl. If you wish to receive email notices when code is submitted then join the mailing list at https://lists.sourceforge.net/lists/listinfo/localupdatepubl-checkin.
Obviously grabbing the latest source runs the risk of getting code that is not yet stable. Use at your own risk!
To build the application, you will need to add or update the reference to Microsoft.UpdateServices.Administration.dll, which can be found on machines with the WSUS console installed.