<?xml version="1.0" encoding="ISO-8859-1"?>
<!DOCTYPE html PUBLIC '-//W3C//DTD XHTML 1.0 Transitional//EN'
    'http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd'>
<html>
<head>
<link rev='made' href='mailto:esr@snark.thyrsus.com' />
<meta name='MSSmartTagsPreventParsing' content='TRUE' />
<title>The GIFLIB project</title>
<script type="text/javascript">
// JavaScript to generate a compact date representation

//
// format date ISO-fashion: yyyy-mm-dd
//
function date_ddmmmyyyy(date)
{
  var d = date.getDate();
  var m = date.getMonth() + 1;
  var y = date.getFullYear();

  return "" + y + "-" + (m<10?"0"+m:m) + "-" + (d<10?"0"+d:d);
}

//
// get last modified date of the 
// current document.
//
function date_lastmodified()
{
  var lmd = document.lastModified;
  var s   = "Unknown";
  var d1;

  // check if we have a valid date
  // before proceeding
  if(0 != (d1=Date.parse(lmd)))
  {
    s = "" + date_ddmmmyyyy(new Date(d1));
  }

  return s;
}
// End
</script>
</head>
<body>
<table width='100%' cellpadding='0' summary='Canned page header' bgcolor="#ddd">
<tr>
<td><h2>The GIFLIB project</h2></td>
<td align="center"><img src="giflib-logo.gif"></td>
<td align='right'><script type="text/javascript">
document.write(date_lastmodified());
</script></td>
</tr>
</table>

<p>The GIFLIB project maintains the giflib service library, which has
been pulling images out of GIFs since 1989. It is deployed everywhere
you can think of and some places you probably can't - graphics
applications and web browsers on multiple operating systems, game
consoles, smartphones, and likely your ATM too.</p>

<p>Yes, this code is he reason GIFs were in Mosaic, the first web
browser that could do inline graphics; it is the implementation
Andreesen and Bina used.</p>

<p>This is very mature, stable, small-footprint code with minimal
dependencies (suitable for use in embedded deployments) that needs only
occasional very minor bugfixes. Test reports from odd platforms and
better regression tests are particularly welcome. Don't try to
redesign it, applications beyond counting would break if you did.</p>

<p>It's "GIFLIB" in caps as a nod to the code's origins in the dark
and backward abysm of MS-DOS, but Unix hackers are encouraged to spell it 
"giflib" in deference to local conventions. :-)

<p>Before October 2006 the GIF format was encumbered by patents on the
LZW compression it uses.  This first became an issue in 1993 when the
patent-holders made ambiguous noises about requiring royalties.  For
some time a subset of this code travelled as "libungif", supporting
decompression but not compression. You can read a more detailed
history <a href="history.html">here</a>.</p>

<p>Note: The 5.x versions change the API slightly in a way that isn't
compatible with older shared libraries.  This was required to fix 
some known problems with the extensions API and with thread-safety.</p>

<p>If you require shared-library compatibility back to ancient
versions, build from 4.2. 4.2 and the 5.0 version are behaviorally
almost identical; the few differences are explained <a
href="gif_lib.html#compatibility">here</a>.

<p>The SourceForge summary page (where you can download the source,
review the project, find links to the bugtracker  and mailing list
pages, or ask to join the project as a developer) is <a
href="https://sourceforge.net/projects/giflib/">here</a>.

<p>People to thank for this code: Gershon Elber, Eric S. Raymond,
Toshio Kuratomi.</p>

<p>If you appreciate this project, and especially if you make money
from it, please <a href="https://www.patreon.com/esr">support
continuing maintainance on Patreon</a>.</p>

<p>GIFLIB technical documentation:</p>
<ul>
<li><a href="intro.html">GIFLIB documentation</a></li>
<li><a href="history.html">GIFLIB's history</a></li>
<li><a href="gif_lib.html#compatibility">Difference between 4.2 and 5.0</a></li>
<li><a href="https://sourceforge.net/projects/giflib/">SourceForge project page</a></li>
<li><a href="https://www.patreon.com/esr">Support this project</a></li>
</ul>

<p>GIF resources:</p>
<ul>
<li><a href="whatsinagif/index.html">What's In A GIF?</a></li>
<li><a href="gifstandard/GIF89a.html">The GIF standard</a></li>
<li><a href="gifstandard/LZW-and-GIF-explained.html">LZW and GIF explained</a></li>
<li><a href="https://en.wikipedia.org/wiki/GIF">Wikipedia on GIF</a></li>
</ul>

<p>To support this ubiquitous code, <a href="https://www.patreon.com/bePatron?u=962938" data-patreon-widget-type="become-patron-button">Become a Patreon patron!</a><script async src="https://c6.patreon.com/becomePatronButton.bundle.js"></script></p>

</body>
</html>
