Форумы / Cotonti / Extensions / New Notifier module

You can already do that with the existing global profile tags and a little javascript. I think the tag you need is {PHP.usr.profile.user_newpm} which will be 1 if the user has a new pm. You could write something like this (JavaScript):

if ({PHP.usr.profile.user_newpm}) {
  alert("You have a new private message");
}

This will show the alert every time until the pm is read, which may not be what you want. You could use a cookie to show the alert only once.

Nevertheless, the feature you describe got me to think about alternative ways to notify a user. I don't plan on implementing other channels such as PM, SMS or push notifications (e.g. APNS), but I will look into an easy way to allow other plugins to add such functionality. I think I'll at the very least include some global template tags to allow you to notify users on-site about updates. Of course there will also be hooks so plugins can hook into the notifier module.