TKDO is a master TODO list with command line and PyGTK interfaces. It takes all your VimOutliner todo.otl outlines, merges them into a single flat list, auto-sorts them, filters them, and adds support for things like contexts and recurring events. It also has a snooze button, to mark tasks as "don't bug me about this for a while". The entire system is based on plain text files, with a GUI to make certain tasks easier and faster. Due to its plain text nature, it's easy to extend or customize the system with short scripts.
ConceptDraw Project is an unique project planning tool designed for efficient planning and tracking of multiple projects. Business activity often requires the planning several simultaneous projects with different dependences and limited resources to drawn on. ConceptDraw Project makes it possible to easily share resources between projects, establish links between them, and organize them in a single workspace to successfully plan projects of any size and complexity.
Zadolbator is a simple reminder component for Jabber server. As it is installed on the server side, it can be used by all users of this Jabber server, and does not depend on the client software used. Its main purpose is to remind you about events such as birthdays or holidays, though it can be used also for keeping your everyday reminders about meetings, things to do, etc. It uses the iCalendar format to store events, so some basic understanding of iCalendar is needed to use it. This also simplifies importing existing events if they're in iCalendar format.