 <p>After wondering for hours through different advices, <a href="http://www.gigoblog.com/2011/01/27/add-mcrypt-to-mac-os-x-server/comment-page-1/#comment-3897">this one</a> worked for me (Installed via MacPorts):</p> <p>Courtesy of <strong>Chris Brewer</strong>:</p> <p>Download and install MacPorts from <code>http://macports.org.</code></p> <p>The following steps are performed in the Terminal:</p> <p>Force MacPorts to update (will only work if Apple's Xcode installed):</p> <pre><code>sudo port -v selfupdate </code></pre> <p>Now, install memcached:</p> <pre><code>sudo port install php5-mcrypt </code></pre> <p>Copy the newly created shared object for mcrypt into Mac OS X’s default PHP5 extension directory:</p> <pre><code>sudo cp /opt/local/lib/php/extensions/no-debug-non-zts-20090626/mcrypt.so /usr/lib/php/extensions/no-debug-non-zts-20090626/ </code></pre> <p>Next, you need to edit php.ini to add the extensions. Find the phrase Dynamic Extensions, and add:</p> <pre><code>extension=mcrypt.so </code></pre> <p>And finally, restart Apache:</p> <p><code>sudo apachectl restart</code></p>