... lotus notes client for linux.
The IBM stuff is RHEL or SUSE though - don't know if there is source for these.
In the repos for ubuntu:
OpenOffice handles a lot of lotus format stuff... and libmeanwhile is a library that provides the basic Lotus Sametime Community Client session functionality along with the core services; Presence, Messaging, and Conferencing.
Also: gnumeric can import Lotus 123.
(And TORCS includes a Lotus GT1