DeforaOS Mixer is a graphical volume mixer written in Gtk+. While initially written for NetBSD's own audio API, it also supports OSS (which is used on systems such as *BSD and Linux).
Mind Map Architect is a mind mapping and brainstorming tool for both single people and teams. It can be used for to do lists, notes, or work planning.
An applicant tracking system.
A powerful build tool with a simple language.