UPX is a free, 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 because of in-place decompression.

What's New in version 3.03:

• implement cache flushing for PowerPC (esp. model 440)
• fix cache flushing on MIPS (>3 MiB compressed, or with holes)
• fix MIPS big-endian
• bug fixes