Xdelta is a popular binary diff-patcher. It's a reasonable alternative to OUP as long as the patched version is known by the modder (e.g., the Mac or PC demo) Before you can install a binary mod (that relies on xdelta for installation) you'll have to set up Xdelta here. Please run the installer for your platform: pcwin32.bat Windows macintel.sh Intel Mac macpowpc.sh Power PC Mac linuxdiy.sh Do It Yourself ^^ The result of the installation is that xdelta3.exe will appear in this folder. (It will be called when installing mods)