Zend Server contains software that is licensed under the LGPL.  You may obtain the source code for the LGPL pieces at the following locations:

libmcrypt:
http://sourceforge.net/projects/mcrypt/files/Libmcrypt/


libming:
http://www.libming.org/Releases

libgmp:
https://gmplib.org/#DOWNLOAD

FreeTDS:
http://www.freetds.org/software.html

libgettext:
http://ftp.gnu.org/pub/gnu/gettext/


If for some reason you are unable to download the software from the designated locations, you may contact us at http://www.zend.com/en/contact-us and we'll supply you with the requested source code.
