PNotes is light-weight, flexible, skinnable manager of virtual notes on your desktop. It supports multiple languages, individual note's settings, transparency and scheduling. Absolutely portable as well - no traces in registry. PNotes.NET edition requires .NET framework 4 Client Profile
Free flexible open source todo manager featuring hierarchical tasks
Task Coach - Your friendly task manager. Task Coach is a free open source todo manager. It grew out of frustration about other programs not handling composite tasks well. In addition to flexible composite tasks, Task Coach has grown to include prerequisites, prioritizing, effort tracking, category tags, budgets, notes, and many other features. However, users are not forced to use all these features; Task Coach can be as simple or complex as you need it to be. Task Coach is available for Windows, Mac OS X, and GNU/Linux; and there is a companion iOS app.
Simple Online Planning
SO Planning is a Simple Online Planning tool. Allows you to plan working periods for each person of your team, in a visual / printable result. Shows a line by person and the corresponding working days. See http://www.soplanning.org for details.
A web-based project management tool for workgroups. Encourage groups and individuals to work collaboratively. This tool aims to be functional and elegant without being complicated or graphically intensive.
RemoteCalendars is a COM-.NET Add-in for Outlook 2003/2007, written in C#. After installing this plugin, every Outlook user should be able to subscribe, reload and delete a generic remote iCalendar (RFC 2445) from Outlook 2003/2007.
BRIM is a MVC framework, written in PHP and based on items with a hierarchical relationship. The list of plugins make BRIM a Information Manager with plugins like bookmarks, a calendar, contacts tasks, notes, RSS etc. The application is multilingual.
Internote provides persistent sticky notes for Mozilla's Firefox web browser. Notes are extremely customizable, and are saved between sessions, reappearing on the page they were created on.
e7NoteIt is a free and small software to pin virtual notices on your desktop. RSS-ticker included.