Multiple PHP versions using phpenv, php-build and php-version
There is a package in the AUR for phpenvhttps://aur.archlinux.org/packages/phpenv/
As well as packages for many different versions of PHPhttps://aur.archlinux.org/packages/?O=0&C=0&SeB=nd&K=phpenv&outdated=&SB=n&SO=a&PP=50&do_Search=Go
First install phpenv:yaourt phpenv
Then install the php versions you need, for example:yaourt php53_29_env
Note: even with this though, you will likely have a problem. Checking the package build, it looks like it is missing the patch to disable PHP automatically being compiled with thread safe features when apache is running a thread safe mpm. Not quite sure since on my systems, I want PHP to enable thread safe code so it will work for me.