"UPX Shell is an ASPack-like GUI shell for UPX (Ultimate Packer for eXecutables). Among it's capabilities are .exe, .dll, .ocx and many other system files packing/unpacking, scrambling those files to protect from unauthorized reverse engineering, full drag&drop support, Internet update facility,... and all this absolutely FREE." UPX Shell has "additional compression" option.

URL: http://iont.virtualave.net/

NOTE: It`s not a spam. Many people on this board use UPX for their programs. I searched for good GUI i found UPX Shell and decided to publish information that UPX Shell exists. I think this software may be useful.