I started using CentOs a while ago, but it seems that the repository choses for more stable versions of programs. For example: I really wish to upgrade my php to at least version 5.5 so I can benefit from the opcode caching that comes with it (currently using a combination of php 5.3 and APC). However when I try a yum update, there are no packages marked for update. I know CentOS backports critical bugfixes of more recent versions into their "old more stable branch", but the new features aren't present. Does anyone know how I can upgrade to the latest version?