libungif4-dev 4.1.4-4build1 (i386 binary) in ubuntu feisty

 This package contains header files needed to compile programs that use
 libungif.
 .
 The libungif library is a specially modified version of giflib which is free of
 the Unisys LZW patent. It can read all GIFs, but only write uncompressed GIFs.
 If you need to be able to write compressed GIFs, you can install the giflib
 packages instead.