Today a developer friend requested to trouble php mcrypt extension on his newly ordered VPS. Most of the time VPS by default comes up with very basic packages. For example, to build and add mcrypt php extension to existing php installation. You would required gcc, make, libtool, libmcrypt, libmcrypt-devel and may other packages.
mcrypt php extension necessary configuration & compilation :
View current php version
PHP 5.3.3 (cli) (built: Jul 3 2012 16:53:21)
Copyright (c) 1997-2010 The PHP Group
Zend Engine v2.3.0, Copyright (c) 1998-2010 Zend Technologies
with the ionCube PHP Loader v4.0.14, Copyright (c) 2002-2011, by ionCube Ltd.