I am trying to create a PBBG (persistent browser based game) like that of OGame, Space4k, and others. My problem is with the always-updating resource collection and with the building times, as in a time is set when the building, ship, research, and etc completes building and updates the user's profile even if the user is offline. What and/or where should I learn to make this? Should it be a constantly running script in the background Note that I wish to only use PHP, HTML, CSS, JavaScript, and Mysql but will learn something new if needed. Cron jobs or the Windows equivalent seem to be the way, but it doesn't seem right or best to me.c