"Osmo, a compact yet feature-rich personal information organizer
for Linux, separates itself from the pack of other calendar
applications due to its light weight and easy-to-use design. The
GPL-licensed Osmo includes a datebook calendar, a to-do organizer,
and a contacts list, all with lots of intuitive options.
"Osmo is so new that it isn't included in many distributions'
software repositories yet, but the source is available through
SourceForge.net. Installing from the source isn't difficult. The
only dependencies are the GIMP Toolkit (GTK+) and libxml2, which
come with most distributions..."