One of the more controversial internet patents is no more – in
the US, at least. On Friday, the patent underlying the Graphics
Interchange Format (GIF) expired in the US, to the relief of makers
of image editing applications. The patent will not expire in
Europe, Canada and Japan until June next year.
CompuServe designed the GIF software in 1987, using
Lempel-Zev-Welch (LZW) compression technology subsequently patented
by Unisys Corporation. In 1994, Unisys and CompuServe reached a
licensing agreement for the technology, and Unisys announced that
it would start to collect royalties on its patent.
This did not go down well within the industry, as GIFs were a
popular way of storing and sending graphics files - and no
royalties had previously been required.
Alternatives were developed, the most notable being the open
source Portable Network Graphics (PNG) format, but they have never
been as popular as GIFs.
The news that the patent has now expired, and that Unisys has no
plans to extend it, has been well received by the majority of web
users – although, according to the BBC, it is likely that the
royalty free GIF will now have a negative impact on PNG
developers.
