Office

• Isogest
  Isogest is a multi-user Web-based groupware suite written in Perl to create a virtual office with a useful API. It has a calendar, contacts, Wiki pages, todo, projects, a HylaFax client, a Web filema...
  
• QT RssApp
  An application for taking notes and synchronizing them with a remote server. ...
  
• NachoCalendar
  NachoCalendar is intended to provide a fully customizable calendar component for Java. ...
  
• myphpim
  MyPhPim is A Multi-User, Personal Information Manager, including email client, addressbook, notes, todo and calendar, Written In PHP. ...
  
• Sunbird
  The Sunbird Project is a redesign of the Mozilla Calendar component. ...
  
• worldpilot
  Worldpilot is a free, open-source, Web-based, multiuser organizer and messenger. It provides an IMAP-based web mail client, contact and address books, sticky notes, "ToDos" and many other. ...
  
• Task Coach
  Task Coach is a simple todo manager to manage personal tasks and todo lists. ...
  
• Diogene87
  Diogene87 is a powerful job scheduling system. It features centralized management, jobs dependencies, start conditions, planning, a log of job activity, job monitoring, statistics for job durations. ...
  
• CALimba
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• HomeCal
  HomeCal is a Web-based scheduling system for use in homes. It has a scheduling calendar for multiple users, Outlook-style notes, and a contacts database. ...
  
• Gcal
  Gcal calculates and prints calendars. ...
  
• anno
  Anno is an ncurses based calendar with the ability to move to the future and past. Anno currently supports the Gregorian and Persian calendars. ...
  
• Celebrat
  Celebrat is a very easy-to-use, non-interactive, text-mode calendar application. ...
  
• PS Cal
  PS Cal is a robust PHP/SQL calendar. It can be used as a personal planner or an event calendar. ...
  
• Pcal
  Prints PostScript or HTML calendars ...
  
• BreakCalendar
  An event management system and calendar using Perl and MySQL. ...
  
• Niki
  Niki is a simple Notes program. ...
  
• Multiuser Address Management System/Book
  MAMS is a Web-based multiuser address management sustem.book (address database). When downloaded, the retrieved addresses can be imported into word-processing or spreadsheet applications; current sup...
  
• Extcalendar
  Extcalendar is a large Web-based calendar application. It allows you to browse the calendar by day, week, month, and category. ...
  
• djpim
  DJPIM is a very simple Web-based interface to a MySQL table that serves as a list of reminders. ...
  
• Memoranda
  Memoranda (formerly known as jNotes2) is a cross-platform diary manager and a personal project management tool. ...
  
• My Calendar
  My Calendar is a lightweight, easy-to-use Web calendar. There is also an included email script that you can have cron run every day to remind you of upcoming appointments. ...
  
• Curses Calendar
  Curses Calendar is a simple console-based journal or diary with a calendar and a to-do list. ...
  
• Little Black Book
  pyLBB is an address book manager. It is portable and allows users to manage contacts, with personal data (name, nickname, address, job information, etc.), along with email addresses, a home page URL,...
  
• KDE Pim
  Collection of KDE PIM applications that can be run in a platform independent way on various platforms, like Sharp Zaurus, Microsoft Windows, Linux and others that support Trolltechs Qt. ...