TechNote (Archived)

Information regarding the licensing of GIF and TIFF files

LZW License Information

The following information is from Macromedia Legal:

You may recently have seen a notice from Unisys stating that you may need a patent license from Unisys if you use software to create GIF or TIFF files or if you post such files on your Web site. If you use licensed Macromedia products to create these files, you do not need a patent license from Unisys.

For several years, Macromedia has had a patent license agreement with Unisys for the LZW compression/decompression patent (U.S. Patent No. 4,558,302) for use in Macromedia trademarked software products. This agreement allows Macromedia customers to use Macromedia products that implement the LZW algorithm without the need for those customers to obtain their own patent license from Unisys.

Examples of permissible uses of Macromedia software that do not require a separate license from Unisys are:

Creating GIF files using Macromedia Fireworks, Flash, or FreeHand and then posting those GIF files to a Web site.
Saving a file in Macromedia FreeHand using the "Save as HTML" feature (which can create a GIF file) and using the resulting file for commercial purposes, including posting the file on a Web site.

These are just two examples of common questions Macromedia receives. However, any licensed use of a Macromedia product that implements the LZW algorithm is permissible without the need for you to obtain a patent license from Unisys.