The first presence program was Finger, designed for ARPANET users. It was designed and written by Les Earnest* in 1971.
Presence systems indicate a person’s online status. For example, whether or not they are online, or accepting messages from other people. Presence information is typically tightly integrated with instant messaging systems such as Skype.–David Ferris
* Curator Ferris remembers the first time he met Les Earnest. Earnest showed him a minicomputer which was dedicated to passing around data on the ARPANET. More specifically, it was a dedicated X.25 processor. Earnest was pleasant, and extremely capable. As you’d expect of a boss of Stanford’s Artificial Intelligence Lab.