do-Organizer!

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.

The ultimate replacement for spreadsheets, mind mappers, outliners, PIMs, text editors and small databases. Suitable for any kind of data organization, such as To-do lists, calendars, project management, brainstorming, organizing ideas, planning, requirements gathering, presentation of information, etc. Its like a spreadsheet, immediately familiar, but much more suitable for complex data because its hierarchical. Its like a mind mapper, but more organized and compact. Its like an outliner, but in more than one dimension. Its like a text editor, but with structure. »

EssentialPIM lets you manage appointments, tasks, notes, contacts, password entries and email messages across multiple devices and cloud applications.

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*. »

MyLifeOrganized (MLO) is a personal task outliner and to-do list manager which will help you to organize your goals, projects and tasks into a tree.

UV Outliner is a small and powerful single-pane outliner. It is intended for creating, organizing, and collecting information.

A fully fledged, free email server solution, an open source project (GPL v2).

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 program helps you organizing your dates and tasks and reminds you of upcoming events.

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.