http://www.os2bbs.com/os2news/Warpzilla.html
Also available (10/13/2006) - Peter Weilbacher has released OS/2 builds of Sunbird (http://releases.mozilla.org/pub/mozilla.org/calendar/sunbird/releases/0.3/contrib/) and Lightning (http://ftp.mozilla.org/pub/mozilla.org/calendar/lightning/releases/0.3/contrib/) version 0.3, the current Mozilla calendaring solutions. Sunbird is a standalone program, and Lightning is an extension for Thunderbird.
See the Mozilla Calendar site for more details.
http://www.mozilla.org/projects/calendar/
Source: OS/2 Warp News and Rumors