The Ultimate Packer for eXecutables
Copyright (c) 1996-2006 Markus Oberhumer, Laszlo Molnar & John Reiser
UPX is a portable, extendable,
high-performance executable packer for several different executable
formats. It achieves an excellent compression ratio and offers
*very* fast decompression. Your executables suffer no memory
overhead or other drawbacks for most of the formats supported,
because of in-place decompression.
While you may use UPX freely for
both non-commercial and commercial executables (for details see the
file LICENSE), we would highly appreciate if
you credit UPX and ourselves in the
documentation, possibly including a reference to the UPX home page. Thanks.
[ Using UPX in non-OpenSource
applications without proper credits is considered not politically
correct ;-) ]
DISCLAIMER
UPX comes with ABSOLUTELY
NO WARRANTY; for
details see the file LICENSE.
This is the first production quality release, and we plan that
future 1.xx releases will be backward compatible with this version.
Please report all problems or suggestions to the authors.
Thanks.
DESCRIPTION
UPX is a versatile executable packer with the
following features:
- excellent compression ratio: compresses better than zip/gzip,
use UPX to decrease the size of your distribution !
- very fast decompression: about 10 MB/sec on an ancient Pentium 133,
about 200 MB/sec on an Athlon XP 2000+.
- no memory overhead for your compressed executables for most of the
supported formats
- safe: you can list, test and unpack your executables
Also, a checksum of both the compressed and uncompressed file is
maintained internally.
- universal: UPX can pack a number of executable formats:
* atari/tos
* bvmlinuz/386 [bootable Linux kernel]
* djgpp2/coff
* dos/com
* dos/exe
* dos/sys
* linux/386
* linux/elf386
* linux/sh386
* ps1/exe
* rtm32/pe
* tmt/adam
* vmlinuz/386 [bootable Linux kernel]
* vmlinux/386
* watcom/le (supporting DOS4G, PMODE/W, DOS32a and CauseWay)
* win32/pe (exe and dll)
* arm/pe (exe and dll)
* linux/elfamd64
* linux/elfppc32
* mach/elfppc32
- portable: UPX is written in portable endian-neutral C++
- extendable: because of the class layout it's very easy to support
new executable formats or add new compression algorithms
- free: UPX can be distributed and used freely. And from version 0.99
the full source code of UPX is released under the GNU General Public
License (GPL) !
You probably understand now why we call UPX the "ultimate" executable packer.