UPX是一个非常好的可执行文件压缩软件，压缩过的可执行文件体积缩小50 -70 ，这样减少了磁盘占用空间、网络上传下载的时间和其它分布以及存储费用。 通过 UPX 压缩过的程序和程序库完全没有功能损失，和压缩之前一样可正常地运行。支持的格式包括 atari/tos，djgpp2/coff，dos/com，dos/exe，dos/sys，rtm32/pe，tmt/adam，watcom/le，win32/pe，Linux/i386 等等，压缩比率也非常的高。-UPX is a very good executable file compression software, compressed executable file size by 50 -70 , thus reducing disk space, Internet upload download time, and other distribution and storage fees. By UPX compressed program and libraries have no function loss, and compression can normally run as before. Supported formats include atari/tos, djgpp2/coff, dos/com, dos/exe, dos/sys, rtm32/pe, tmt/adam, watcom/le, win32/pe, Linux/i386, etc., compression ratio is very high.