I have a PHP script that I need run continuosly. A CRON will not help as a CRON can only run once every minute max. Now the best way to do this is to create a daemon. It is also important that there can't be 2 instances of the daemon running at the same time. The best way to do this is to use [url removed, login to view] Monit will ensure that there is only 1 instance running all the time. It will ensure that if for any reason the daemon dies or is not running, a new instance will be automatically be started. It will also ensure that only a single instance will be running at any given point of time.
It is a very simple project if you have the experience and have done it before.