There are some howto's outside, whcih describe the way to install multiple PHP-Versions on one Server, and make them choosable
(for example:
http://cweiske.de/tagebuch/Run…ozen%20PHP%20versions.htm
http://www.howtoforge.com/how-…ispconfig-3-debian-wheezy
I would love to see a Option in i-mscp, where such an option is chooseable via GUI.
With a good wiki-entry, how to install other PHP-Version and make customers choosable, which one should be used for their webspace, this will simplify upgrading websoftware a lot.