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.
JTrac is a generic issue-tracking web-application that can be easily customized by adding custom fields and drop-downs. Features include customizable workflow, field level permissions, e-mail integration, file attachments and a detailed history view.
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.
BORG is a calendar and task tracking system written in Java. The calendar provides a nice month view, month-print, email reminders, popup reminders and to do list. The task tracker tracks issues through various states.
private digital diary
Lifeograph is a diary program to take personal notes on life. It has all essential functionality expected in a diary program and strives to have a clean and streamlined user interface.
Online project management and issue tracking with team collaboration, custom fields and forms, JasperReport reporting, user management, multiple access levels, tasks, projects, time tracking, task change history, multiple attachments, Gantt graphs.
Nomad PIM is a free extensible personal information manager. It contains modules for personal notes, journal, address book, personal finances, task management, time tracking and evaluating basic fitness measurements.
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.