title: Installing PHP xdiff on Windows with WAMP
body: <p>I can't believe this hasn't been asked before, but here goes:</p>
  
  <p>I'm trying to install xdiff on Windows (64-bit) using WAMP and PHP version 5.3.</p>
  
  <p>pecl.php.net doesn't offer a .dll file for this combination so I tried downloading the 5.3 x86 files and the 5.5 x64 versions, but neither worked.  The x86 version generated the following warning in the apache logs:</p>
  
  <blockquote>
    <p>[Thu Jun 05 15:55:47 2014] [warn] Init: Session Cache is not configured [hint: SSLSessionCache]
    PHP Warning:  PHP Startup: Unable to load dynamic library 'c:/wamp/bin/php/php5.3.13/ext/php_xdiff.dll' - %1 is not a valid Win32 application.\r\n in Unknown on line 0
    <br />
    <b>Warning</b>:  PHP Startup: Unable to load dynamic library 'c:/wamp/bin/php/php5.3.13/ext/php_xdiff.dll' - %1 is not a valid Win32 application.</p>
    
    <p>in <b>Unknown</b> on line <b>0</b><br /></p>
  </blockquote>
  
  <p>The x64 version generated this warning:</p>
  
  <blockquote>
    <p>[Thu Jun 05 15:58:16 2014] [warn] Init: Session Cache is not configured [hint: SSLSessionCache]
    PHP Warning:  PHP Startup: Unable to load dynamic library 'c:/wamp/bin/php/php5.3.13/ext/php_xdiff.dll' - The specified module could not be found.\r\n in Unknown on line 0
    <br />
    <b>Warning</b>:  PHP Startup: Unable to load dynamic library 'c:/wamp/bin/php/php5.3.13/ext/php_xdiff.dll' - The specified module could not be found.</p>
    
    <p>in <b>Unknown</b> on line <b>0</b><br /></p>
  </blockquote>
  
  <p>At that point, I went back and read the readme file a little more closely and discovered the following line:</p>
  
  <blockquote>
    <p>This extension requires libxdiff (<a href="http://www.xmailserver.org/xdiff-lib.html" rel="nofollow">http://www.xmailserver.org/xdiff-lib.html</a>).</p>
  </blockquote>
  
  <p>Okay, fair enough.  Following the advice on <a href="http://blog.brainmassage.co.uk/2010/10/php-xdiff-libxdiff-on-windows/" rel="nofollow" title="this page">this page</a> I compiled libxdiff but then I got to the step that read</p>
  
  <blockquote>
    <p>Once compiled you need to copy all the headers and libraries into the appropriate PHP library directories.</p>
  </blockquote>
  
  <p>And I have no idea what the "appropriate PHP library directories" are nor what files I'm supposed to be copying, nor even if the missing libxdiff is the problem (or if the real problem is that the .dll file I'm using is just incompatible with PHP 5.3 x64 and I should be trying to compile the PECL extension instead of libxdiff).</p>
  
  <p>Does anyone have any advice?</p>