CentOS 5.x comes with PHP in version 5.1.6 which is pretty old those days. There are already quite some web applications that have dropped PHP 5.1.x support which makes it impossible to install them on a CentOS 5.x installation. With the release of CentOS 5.6 additional packages called php53, php53-common, php53-ldap, etc. have been released which could replace the 5.1.6 default version of PHP if you don't have other RPM packages that depend on the original php packages. Since the php and the new php53 packages do install their resources into the same directories you can't install both of them in parallel. Instead of faking empty php packages to be able to install all php53 packages without conflicts and missing dependencies I decided to go for a third party PHP installation provided by AtomiCorp.
Some Python scripts that I've written have to communicate with an Oracle Database. To be able to do so you have to install a Python module that implements the needed Oracle bindings against the Python Database API. Usually those modules aren't part of recent Linux distributions due to license restrictions. Since I haven't really found some easy and straight forward howto or tutorial how to install the cx-oracle Python extension module on CentOS 5.x I decided to write my own little tutorial.