Acronym: Program for Internet News and E-Mail
Recursive acronym: PINE Is Not Elm
A cross-platform E-Mail Client and Newsreader (available for UNIX-like and Windows computers), it is purely textmode but allows even the slowest computer with the most basic monitor e-mail access. Includes spell-checking, mailboxes, and more.
Pine has been officially available since 1989 and still actively used.