Group Calendar Project


Some preliminary statements:

  1. Determine current availability of group calendaring software that is compatible with Linux server and MS-Windows or Linux desktops.
  2. Document development support, resources, initiatives and standards.
  3. Develop any missing functionality.


Products of primary interest

KOrganizer (License: GPL)
Client software for Linux KDE. Included in RedHat distibution.
GNOME Calendar
Client software for GNOME. Included in RedHat distibution.
Modular Calendar Access Library
A client-server library being developed now, under LGPL. They also run a server for testing against. (Note: It was developed as an implementation of the ICAP protocol, which is a variant of the CAP protocol modified for use with IMAP mail servers. A document called draft-oleary-icap defining ICAP appeared on one of the IMC or IETF websites at one time...)
PHP3 support for ICAP
Requires MCAL library from above and PHP 3.0.12 or later.
A simple multi-user calendar and to-do list manager designed for use in Linux KDE, implemented using a MySQL database server.
Rosenet Calendar
Simple community calendar, implemented with PHP3 and MySQL.

Proprietary products of Interest

StarOffice Schedule
Stardivision was recently acquired by Sun ( story, TechWeb story) and this suite is planned to be made available via a similar licence as Java. This suite includes Group Scheduling client and server for both Windows and Linux. (We ordered a CD which contains the server on Sept 6 as the server software is not available for download. This is not a Free Software solution, but might provide a good migration path to one as the Group Calendaring standards solidify and Free Software is written.)
Netscape Calendar Server, produced by Sun | Netscape Alliance
Netscape Calendar Client software (A product of AOL) is available for free download on all required platforms. When trying to find out details about buying the server I was forwarded to a reseller Itraware who indicated that the Netscape Calendar server is not yet ported to Linux, but soon will be. (RWM: The Canadian office at 155 Queen does not exist.)

Other products

Note: The main reasons for lower interest in these products include lack of Linux support in some, cost for small networks (our main interest is in the <30 desk environment), and lower integration with existing Email services (Replacing standard email services with the services of these products would cause additional support costs).

HP OpenMail
Server now available for Linux. Supports Outlook on the Windows desktop. Researching alternate clients that would have similar User-Interface on both Linux and Windows to avoid re-training issues. Update: HP OpenMail isn't distributed anymore. (thanks to Ralf Habackerfor for the update)
Lotus Domino R5
Server for Linux in Beta. Notes client not yet available for Linux. Web browser can operate as client.
Novell Groupwise
No server or client for Linux (Or any other UNIX). They did write an interesting article responding to Microsoft.
Microsoft Exchange Server
No server or client for server platforms other than Microsoft NT. Does not integrate well with existing standards-based Email services.

Standards and organizations

IETF Calendaring and Scheduling working group documents (copies may be stored here for convenient access):

Draft Implementors' Guide to Internet Calendaring
Describes the relationship between the various internet calendaring and scheduling protocols (see below) as well as works in progress. Intends to provide a context for these protocols, assist in their understanding, and ultimately help implemntors in the design of their internet calendaring and scheduling systems.
Calendar Access Protocol (CAP)
Specification for an Internet protocol that permits a Calendar User (CU) to utilize a Calendar User Agent (CUA) to access a Calendar Store (CS).
Internet Calendaring and Scheduling Core Object Specification (iCalendar)
Corrects and clarifies iCalendar RFC-2445. Also defines the format for specifying iCalendar object methods. An iCalendar object method is a set of usage constraints for the iCalendar object.
Calendar attributes for vCard and LDAP
Defines 3 mechanisms for Calendar User Agents to obtain a URI to a user's calendar and free/busy time.
  • Manual transfer of the information;
  • Personal data exchange using the vCard format; and
  • Directory lookup using the LDAP protocol.
iCalendar Transport-Independent Interoperability Protocol (iTIP) Scheduling Events, BusyTime, To-dos and Journal Entries
Specifies how calendaring systems use iCalendar objects to interoperate with other calendar systems. Also, adds semantics for group scheduling methods that permit two or more calendar systems to perform transactions such as publish, schedule, reschedule, respond to scheduling requests, negotiation of changes or cancel iCalendar-based calendar components.

ICalendar Real-time Interoperability Protocol (iRIP)
Specifies a binding from the iTIP to a real-time transport.
iCalendar Message-Based Interoperability Protocol (iMIP)
Specifies a binding from the iTIP to email-based transports.

Personal Data Interchange
A project of the Internet Mail Consortium. The website contains a complete list of shipping products for vCalendar, an older version of the iCalendar specification.

People working on project

If there are any comments, additions, deletions please contact one of us:

Related Projects:

Last Modified: $Date: 2003/03/14 14:13:16 $ UTC