Mitsuharu Arimura's Data Compression Pointers
Very large list of links, including books and lecture notes, benchmarkings, archives, image/graphic compression, fractal compression, wavelets, video and audio compression, and links to other link lists.
http://www.hn.is.uec.ac.jp/~arimura/compression_links.html

Maximum Compression
Maximum compression features reviews/benchmarks designed to show/test the best lossless data compression software (mainly command line compression programs).
http://www.maximumcompression.com/

USENET Compression FAQ
This URL takes you to a compression FAQ that explains compression to technical people as well as describing the various programs, and what they do to users.
http://www.faqs.org/faqs/compression-faq/

Dr Ross's Compression Crypt
Dr Ross's Compression crypt contains compression algorithms by Ross Williams, and other information about compression.
http://www.ross.net/compression/

SBC Archiver
SBC is lossless compression program with fast and modern compression and encryption algorithms providing top class compression ratios not even comparable to ZIP technology. [Shareware Win 9x/NT]
http://www.geocities.com/sbcarchiver/

Groovyweb Compression Tutorials
Compression tutorials, links to other compression sites and compression downloads.
http://www.groovyweb.uklinux.net/index.php?page_name=compression

Dresser Rand Compression Services
Dresser-Rand is a leading supplier of energy conversion solutions worldwide. D-R designs, manufactures, sells and services large, highly engineered centrifugal & reciprocating compressors, steam & gas turbines & control systems.
http://www.gascompressors.com/

SCFM Compression Systems Co.
Custom gas compression units for gas production and distribution, landfill gas, fuel gas boosters, and custom air compression.
http://www.scfm.com/

AirZip Image Compression
AirZip provides software to persistently secure sensitive information and intellectual property, and to compress and accelerate data.
http://www.airzip.com/

Bodycote Hot Isostatic Pressing
Specialize in casting densification, PM, Near-Net shapes, and reclamation of castings.
http://hip.bodycote.com/