By Prince McLean

Published: 09:05 AM EST

Apple has made major changes to iCal in Mac OS X 10.5 Leopard, introducing integration with its own new WebDAV-based iCal Server included in Leopard Server. Here's a comprehensive history of software-based calendar applications and a look at what's new in iCal 3.0.

This report goes to great lengths to follow the origins, history, and maturity of software-based calendar applications. For those readers with limited time or who are only interested in what's due in Leopard, you can skip to page 3 of this report.

iCal Origins

Beyond accessing a calendar to simply look up the date, the idea of calendaring and organizing event information dates back to 1973, with the release of PLATO Notes by the University of Illinois' Computer-based Education Research Laboratory. Originally designed as a way to track bug reports at CERL, the system developed into a way to organize distributed collections of Notes, secured by permission access lists, organized by date, and eventually shared between other systems.

Developers of PLATO Notes, including Ray Ozzie, Tim Halvorsen, and Len Kawell, later left the university and continued development work at other companies. At Digital, developers from CERL produced a product called DECNotes. Ozzie went to work for Lotus Development.

Desktop Organizer Software

The idea of scheduling and organizing events with desktop PC software dates back to Lotus Agenda (below), a DOS program from 1987 that billed itself as a 'personal information manager' and was commonly described as a "spreadsheet for ideas."

Lotus had earlier released the wildly popular 1-2-3 spreadsheet. The company was founded by Mitch Kapor, an early PC software pioneer who had gotten started at VisiCorp, the maker of VisiCalc, which was both the first computer spreadsheet and the killer app that launched the market for personal computers with the Apple II in 1979.

Lotus Agenda pioneered data organization in a novel way using a flexible database. Users assigned new data entry Items to multiple Categories of their own design. They could then relate together ideas using Filters to search, and present items in Views. This made the system powerful, but its complexity gave it a steep learning curve.



Lotus Notes

In 1984, Ozzie had left Lotus to start Iris, a project funded by Lotus to develop a system similar to PLATO Notes for use on personal computers. The task of migrating Notes' online discussion, email, contact and document directories to the PC was a bit much for PCs of the early 80s; Notes had to devise a way to distribute much of the work to a dedicated server. It also had to roll a lot of its own operating system functionality, since DOS didn't offer much sophistication underneath its applications.

The system was released in 1989 as Lotus Notes 1.0 (below). It ran on both DOS and IBM's OS/2. The new system launched the idea of client/server applications on PCs (as opposed to using a mainframe with attached dumb terminals) and kicked off the concept of groupware: networked collaboration, messaging, group scheduling, centralized contacts, and organized libraries of documents. Notes worked as a system of building blocks for creating integrated, custom corporate applications.



Graphical Calendaring

In 1990, PeopleCube introduced the MeetingMaker calendar for the Mac, which introduced graphical group scheduling. FirstClass (now owned by Open Text) arrived in the same period, delivering distributed messaging and online collaboration for the Mac that grew from origins as a graphical online bulletin board system. In the mid 90s, FirstClass developed into a full groupware system with scheduling features.



In 1992, Lotus released Organizer (above) for Windows, a graphical replacement for Agenda which presented events in handheld planner interface. By the mid 90s, "Personal Information Manager" had become a popular buzzword. While Organizer maintained a clear lead on the PC, there were several competing calendar programs on the Mac:

• Microsoft's 1992 Schedule+ (above) was sold for the Mac and Windows.
• Now's Up-To-Date and Contact.
• Datebook and TouchBase Pro, purchased by Aldus in 1993.
• Claris Organizer (below) appeared in 1995.

Claris Organizer incorporated Calendar, Contacts, Notes, and Tasks into a single interface. Developers of the Palm Pilot organizer were influenced by that design in creating their PDA, and the company later used Claris Organizer as its Palm desktop software on the Mac. Those same concepts would later show up Microsoft's Outlook, which debuted in 1997.

On page 2 of 3: Microsoft Advances into Desktop Calendaring; The Intersection of NeXT, Apple, Claris, and Microsoft; The Arrival of Jean-Marie Hullot's iCal; and Groupware Calendaring.