OrgCalendar!

Microsoft Outlook, part of the Microsoft Office Suite (not to be confused with Microsoft Outlook Express), is a personal information manager that lets you manage your e-mail, calendar, contacts, and tasks.

Rainlendar is a feature rich calendar application that is easy to use and doesn't take much space on your desktop. The application is platform independent so you can run it on all major operating systems: Windows, Linux and Mac OS X. The appearance can be customized with skins and you can even mix different skins together. It is possible to use Rainlendar with other calendar applications too. Rainlendar uses the standard iCalendar format to store its events and tasks so you can easily transfer them between applications. You can also subscribe to online calendars including the Google Calendar and edit your Outlook appointments directly in Rainlendar*. »

An offline calendar without any other calendar integration. You can easily create recurring events and setup reminders, it can also display week numbers.

CalenGoo gives you a fast and easy way to access and change your Google Calendar (or Google Apps Calendar) with your Android device. It can either work with the built-in calendar or it can sync directly with Google.

This application is a software calendar with appointments notes, tasks, alarms and contacts that provides seamless integration and interactivity with the desktop background. You can organize your data in layers and share them with other people on a local area network.

BORG is a combination calendar and task tracking system. The calendar supports all sorts of appointments and also a simple todo list. The calendar functionality is similar to that of other PIMs, such as Microsoft Outlook, Mozilla Calendar, Palm Desktop, Yahoo Calendar, etc... The Task Tracker goes way beyond todo's and might better be called a project tracking system.

BEAUTIFULLY DESIGNEDDigiCal’s diary planner and organizer provides a clear and beautiful overview for your events and appointments.• Conveniently switch between 7 calendar views (day, week, week agenda, month calendar, text month, year and list view in portrait and landscape mode).• The slick dark theme allows for better visibility in low-light settings and night mode.• Event keyword image matching available in all 27 languages!• 6 highly customizable widgets with different theme styles and views: (FREE: list, day, day list, day grid widgets; PREMIUM: 2 extra widgets –text month and month calendar widget)• Intuitive navigation between days, weeks and months with zoomable day and week view. »

MemoCalendar.net is a light-weight and easy-to-use online calendar like a usual memo calendar on the wall. Behind every day a small note can be deposited. MemoCalendar.net is free and without registration (login) usable.

KOrganizer is the calendar and scheduling component of Kontact, the integrated personal information manager from KDE.

AnCal stores yours appointments, tasks and notes, which you can easily add and edit. You can also set alarms for selected items and see day, week and month reports of your appointments.

Quickly see the time until your next meeting from any of your calendars. Click on the button to be taken to your calendar.

Experience the ease of use of a weekly calendar in the palm of your hand! Easy Calendar is the new easy way to plan your day. Designed around frequent tasks, Easy Calendar allows anyone to create new events with just a few taps!

Zoho Calendar is a free online calendar application that helps you to track your appointments and meeting schedule, send invitation and track RSVP's, share and publicize your calendars. You can aslo access your Zoho Calendar from mobile phone.