Widely used commercial systems that provide functionality comparable to the Calendar Tool include

• Microsoft Outlook,
• Apple iCal,
• Netscape Calendar,
• Now Software Now-Up-to-Date,
• Claris Organizer (no web site available)

Each of these systems provides a wide variety of calendar and scheduling functionality. In terms of such functionality, the goal for the Calendar Tool is to provide the important core features found in these tools, not the full range of features found in all of them. The Calendar Tool does provide modest functional improvements in three areas, when compared to most commercially available tools. These improvements are:

1. more flexibility in viewing and selecting from lists of possible meeting times that are generated by the automatic scheduler;

2. more flexibility in specifying recurring events;

3. more extensive forms of view filtering.

The goals for the Calendar Tool relating to public domain source code and sound pedagogical development are not met by any of the above commercial systems.

A detailed review of each related tool follows in these subsections:

• Outlook review
• iCal review
• Netscape Calendar review
• Now-Up-to-Date review
• Claris Organizer review