I was having a problem with my RHEL 6.1 installation where I needed to install xdebug for php development debugging. My installation was RHEL 6.1 with php version 5.3.3. I ended up installing the webtactic yum repo, then tried installing php54w but got a conflict with php-common. I ended up deciding to remove the existing php 5.3 installation via yum, then went ahead and installed the php54w version along with the php54w-devel package (needed for phpize). After doing so I was finally able to follow the instructions at How To configure XDebug to complete the installation. The key being that I had to update the /etc/php.d/xdebug.ini file to make it look like this. After doing so, and restarting apache, I’m able to debug php programs on redhat with netbeans.
;Enable xdebug extension module