This code is from libungif 4.1.0

In theory it comes from (URL probably broken):
http://prtr-13.ucsc.edu/~badger/software/libungif.shtml

This seems to be the new location of the libungif project:
http://sourceforge.net/projects/libungif

But I don't think this works any more. I generally dig up 
source RPMs to dig up the code.  

Changes:
 o Select only lib files needed.
 o Fix a few warnings about unused variables. 
 o Hack private include file to avoid VersionString warnings.
 o Hacked in O_BINARY support whereever O_BINARY is defined.

History:

This package was originally written by Gershon Elber in 1990 on an IBM PC
under MS-DOS using Borland Turbo C. He made it portable to several UNIX
environments.

v1.0 (4 Jul 89) created by Gershon Elber.
v2.1 featured substantial changes and additions by Eric S. Raymond.

Status:

The libungif is now an integral part of GIFLIB.
Current maintainer is Eric S. Raymond.
GIFLIB is not under active development, but bug fixes are being accepted.

License:

The GIFLIB is available under terms of MIT License.
Also, refer to COPYING file.