www.boutell.com wrote:
GIF support has been restored in gd 2.0.28. The well-known patents on LZW compression held by Unisys have expired in all countries. British Telecom and IBM may hold related patents but have never chosen to require royalties for GIF applications, to the best of my knowledge. I am not a lawyer and cannot give legal advice regarding this issue. PNG remains a superior format especially if lossless truecolor images are needed.
http://www.boutell.com/gd/manual2.0.28.html
http://www.boutell.com/gd/