Running Linux, 5th Edition - Matthias Kalle Dalheimer [146]
To be fully functional, an OGo installation needs several additional components, such as an IMAP server, a PostgreSQL database, a working mail transfer agent, and a directory service such as OpenLDAP.
You can find more about OGo at http://www.opengroupware.org.
phpGroupWare and eGroupware
Coming from a common PHP codebase, phpGroupWare and eGroupware offer groupware functionality primarily through browser-based access. Users can manipulate and view their own and other people's calendars and contact information and manage files, notes, and news items. Several additional optional applications are available.
Both servers need to be installed on top of an existing web server and database and can make use of a mail server for sending and accessing mail via IMAP, if one is available.
More information about phpGroupware and eGroupware is available at the following URL: http://www.phpgroupware.org and http://www.egroupware.org.
OPEN-XCHANGE
The OPEN-XCHANGE server started out as a proprietary product, but has since been put under open source licenses. Like many other solutions, it builds on and works with other server components, such as the Apache web server and OpenLDAP. On top of those, it offers several standard modules, such as a calendar and contacts and tasks management, as well as document and project management, and discussion forum, knowledge base, and web mail components.
Technologically, OPEN-XCHANGE is different from many of the other solutions in that it is built using Java technologies. This makes it attractive if integration with existing Java-based applications is desired.
Read more about OPEN-XCHANGE at http://www.open-xchange.org.
Closed-source products
In addition to the free and open source solutions described in the previous sections, several commercial and nonfree alternatives are available as well. All of them are powerful and full-featured, and support Linux as a native platform either exclusively or along with other platforms. The most important ones include Novell Groupwise, Novell SUSE Linux Openexchange (based on OPEN-XCHANGE), Lotus Notes & Domino, Oracle Groupware, and Samsung Contact and Scalix (both based on HP Openmail). The web sites of the respective vendors and products have more information on each of them.
LDAP: Accessing Global Address Books
One of the benefits of having information centrally stored and maintained is that changes and updates need only be done in one place and are then available to everyone immediately. This is especially important for contact information, which is prone to change and become out of date. The ability to quickly search through large amounts of contacts flexibly is another requirement that becomes more important the larger the organization gets, with all its internal and external communication partners. To meet this need, so-called directory services have been developed, along with a standard protocol to access and query them. The protocol is Lightweight Directory Access Protocol (LDAP), shared by a number of implementations, including the open source implementation OpenLDAP and (with typical Microsoft extensions) Microsoft Active Directory. OpenLDAP can be integrated with many of the groupware systems described in the previous sections.
The address book components of all major groupware suites allow the administrator to tie them to one or several LDAP servers, which are then queried for contact information and will be used for email autocompletion when composing emails. In Kontact, the LDAP configuration dialog for adding a new LDAP query host looks