PHP3 and PHP4

Hi... I have an old box that is about to pass through, to be an ex box, etc (c) monty pythons... I'm transfering its datas to a very nice and powerfull SuSE 7.2 box, that I installed first with PHP4. As the former box was running php3 only, I was wondering if it was possible to run BOTH php3 and php4... Thanx in advance Stephane