Lotus Notes Based

extendedReach Software
Help desk and related solutions based upon IBM's Lotus Domino platform.
http://www.ersoftware.com

GeoCom Helpdesk
Compact Lotus Domino based helpdesk software with customizable scheduler for user and customer support.
http://www.geocom.de/geocom/page/uk/hd.html

Tracker Suite
A Lotus Notes help desk solution, which offers FAQs and knowledge base functionality.
http://www.trackersuite.com/frame_help_desk_software.html

Velocity Integrations Software
A Lotus Notes service desk and problem management solution.
http://www.velocityintegrations.com