Oh ok sorry for posting wrong section.
I installed php 5 like in the wiki written. Ok the installation worked and joomla is telling me it worked too. In the system info of Joomla is PHP 5. So the installation worked, but the configuration to work with webapplications doesnt work.
http://wiki.contribs.org/PHPBecause in the wiki it says to install mcrypt for joomla i wanted to do that.
When I saw that the 2 links of the rpm is outdated, i started to look up for other files of this two and found this on
http://rpms.famillecollet.com/el5.i386/ I downloaded another version of this and started to installing it
php-common-5.3.6-1.el5.remi.i386.rpm and php-mcrypt-5.3.6-1.el5.remi.i386.rpm.
But at the installation it says there are dependcys are missing.