phpGroupWare (formerly known as webdistro) is a multi-user groupware suite written in PHP. Its provides a Web-based calendar, todo-list, addressbook, email, news headlines, and a file manager. The calendar supports repeating events. The email system supports inline graphics and file attachments. The system as a whole supports user preferences, themes, user permissions, multi-language support, an advanced API, and user groups.
phpSched is an application for the creation and management of shift-based schedules. Current features include template creation, managing multiple departments, multiple shift types (regular shift, Supervisor shift, etc.), email notification, asking for or offering shifts, schedule publishing, and validation.
Tobedone is a Web-based Java applet project management tool which organizes complex projects in tree structures and offers you many manipulation tools. You can give specific tasks priorities, assign them to persons, create and delete databases, give permissions to users, sort project tasks by priorities, dates, etc, and a lot more.
ttm is a simple but flexible command-line based Perl program for managing lists of tasks. Arbitrary properties can be attached to each task. Standard properties such as `priority', `status' and `categories' are used to provide different ways of viewing the task list. Editing is done with your favourite text editor.
Wcal is a Web-based calendar and planner especially suitable for multi-user setups in an intranet. It features the ability for several users to have their own or shared calendars, read-only views, Weekly and monthly repeating events. It uses the Web server's access control methods, and allows a separate access control definition for each user.