Linked Notes is a Wiki style notepad for your desktop computer or USB Flash Drive. It provides a simple way to organize your notes and keep them private.
A free and open source tool for knowledge management
Relations RCP is a tool for knowledge management.
Viki/Deplate is a personal wiki for Vim.
vimwiki is a personal Wiki for Vim.
ZuluPad – Combines the best parts of a notepad with the best parts of a wiki
WikityWidget – A personal wiki. Stickies on steroids
Confluence is enterprise wiki software for sharing and editing content, online collaboration, knowledge management, document management, file sharing, and more. Used for open source and commercial applications. Free 30-day evaluation available.