efficient live-compressor for executables

 UPX is an advanced executable file compressor. UPX will typically
 reduce the file size of programs and DLLs by around 50%-70%, thus
 reducing disk space, network load times, download times etc. The
 current version can compress executables for DOS, Linux/ELF (i386,
 amd64, ppc32) and some other files for different OS.
 .
 NOTE: This package is based on the UCL library, which is licensed under GPL.