I know that most every forum has its own persistant world these days. For those of you who don't know, a persistant world is "a virtual world that continues to exist even after a user exits the world and that user-made changes to its state are, to some extent, permanent." In a PW all postings take place in one universe, often you will find multiple geographical locations encased in one category and characters are free to roam from place to place in one continuous, ever changing story world.
This means that even if you are not logged in events may occur that may/may not impact your character. A Pw would require active postings as well as a GM or Gamemaster.
If anyone is interested in developing a persistant world please post your ideas in the comments section or PM one of your mods.
~Birdy