Mozilla Thunderbird Calendar
Mozilla Lightning has received some criticism for having a clunky calendar interface. Even so, without the high cost of Outlook, and the ability to download a variety of addon programs, you may still find the Mozilla Thunderbird calendar preferable to Outlook. Lightning allows you to view your tasks and your calendar items in different tabs. If need be, you can have your computer sound an alarm when it is time to switch tasks.
It is possible to save your Mozilla Thunderbird calendar on an FTP server for use of every computer on a network. Likewise, you can create a calendar for your entire family, by using a different calendar file for each person.
Entries in the Mozilla Thunderbird calendar are called "events." Events include items that fall on a particular day (or days) and at particular times. Event examples include birthdays, meetings, or vacations.
Alternatively, there are tasks. Tasks are items that you have to take action on. These may or may not be linked to a specific time period. For example, writing an article would be considered a "task."
Even without the color-coding, you can associate different tasks with different labels. For instance, if you are familiar with the Getting Things Done productivity methods, you could create labels such as "waiting for," "defer," "action required," etc.