http://clay.ll.pl/osmo/Osmo is a handy personal organizer which includes calendar, tasks manager and address book modules. It was designed to be a small, easy to use and good looking PIM tool to help to manage personal information. In current state the organizer is quite convenient in use - for example, user can perform nearly all operations using keyboard. Also, a lot of parameters are configurable to meet user preferences. On the technical side, Osmo is GTK+ based tool which use plain XML database to store all personal data.
Start via Menu->Personal->Osmo, or by typing osmo.
Note Version 1.2 will run on pupversions 2.xxx however Osmo-0.2.0, due to requiring gtk>=v2.10.0, is for pup 3.xxx series.