erc-notify.el is a EmacsIrcClient module that allows you to keep track of the online status of certain people.
Notify is not enabled by default. To enable it use
customize-variable RET erc-modules.
You get a new /-command,
/notify. Use it as follows:
/notify by itself lists the users online which are on your notification list.
/notify nick [nick …] toggles that nick. Meaning, if the nick is on the list, it will get removed, otherwise it will be added.
The status of the nicks is checked every
erc-notify-interval seconds, 60 by default.
Note that you can also use variable