"Transient visual notifications are employed extensively in
desktop applications to provide users with passive updates about
application status or system events. Some typical usage scenarios
include notifying users when they receive new e-mail, when an
instant messaging buddy signs online, or when a CD finishes
burning.
"The current status of notifications on Linux
"The most widely-used notification system on the Linux desktop
today is based on the FreeDesktop.org (FDO) notification
specification. The spec, which was authored by the developers
behind the Galago project, describes a standardized API that can be
accessed through the desktop-neutral D-Bus interprocess
communication protocol to display visual notifications on the
user's desktop. The authors of the spec supply a reference
implementation called notification-daemon that is shipped with the
GNOME desktop environment in many popular Linux distributions. An
accompanying library, called libnotify, provides a lightweight
abstraction layer that helps applications interact with the
daemon."