Lempel-Zif-Welsh

(L-Z-W)

A data compression technique named after the developers. A common use for LZW compression is in the GIF graphic file format. The LZW patent is owned by Unisys (U.S. Patent 4,558,302) who angered the entire web community by deciding to charge a license fee in 1995 after allowing free use for a long prior period. The basic patent expires in June of 2003 but variations on it run 20 years further and more applications could be filed.

More Information

• Data Compression Info
• License Information on GIF and Other LZW-based Technologies