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This article provides information about licensing issues regarding the .giffile format and the Lempel Ziv Welch (LZW) data compression anddecompression technology. Unisys has patented this technology and requiresthat anyone using this technology obtain a license. This article containslinks where you can get more information about the required license.
The LZW data compression and decompression technology is covered by UnitedStates Patent No. 4,558,302, Japanese Patent Numbers 2,123,602 and2,610,084, and patents in Canada, France, Germany, Italy, and the UnitedKingdom.
Microsoft has obtained a license from Unisys to use the .gif file formatand other LZW technologies covered by the Unisys-owned U.S. and foreignpatents in a number of Microsoft products.
However, this license does not extend to third-party developers usingMicrosoft development products to develop applications. Third-partydevelopers must have a license from Unisys in the form of a writtenagreement.
If you would like to use, sell or distribute any hardware or software usingor converting the .gif file format or LZW-based technologies, you mustobtain a license from Unisys.
For more information about the licenses required to use thistechnology, contact Unisys. For more information about hardware and software vendor contact information, visit the following Microsoft Web site: -