An Open Look at Groupware
Open source groupware is better than ever, but for those seeking to replace Exchange, some caveats apply. Jim Conley examines the state of open source groupware and why it matters in a Microsoft shop.
Microsoft pulls the plug on Exchange 5.5 Server on Dec. 31 after eight years
of steady service. While most of the Exchange 5.5 population has migrated to
Exchange 2000 Server or Exchange Server 2003, some analysts estimate that as
many as 25 million seats will still be on Exchange 5.5 at the beginning of next
year. Without support from the mother ship, admins are on the lookout for their
next platform--which may not be Microsoft. And as Microsoft is finding with Linux,
open source alternatives are enticing many of those looking to switch.
Open Source vs. Runs-On-Linux
A quick refresher for the Windows crowd--open source and "runs-on-Linux" aren't
synonymous, especially when talking about Exchange alternatives. Bynari Insight
Server is an excellent Linux-based Exchange replacement, but isn't open source.
Projects such as OpenGroupware.org and Open-Xchange are open source. In theory,
an administrator could build an open source groupware solution with no costs
beyond hardware and developer time. In practice, most groupware servers running
on Linux (including those based on open source) use some closed-source components,
especially if Outlook is the intended client.
A variety of open source servers replicate the basic functionality of Exchange
5.5, but accessing data from a Windows desktop requires either a proprietary
connector for Outlook or a user base willing to try a Web interface to access
much of anything beyond e-mail. Outlook connectors may carry substantial licensing
fees, but they do offer the most painless transition on the client side. Users
know Outlook, and many power users rely on Outlook. While Novell has announced
a future port to Windows of its popular open source groupware client Evolution,
for now Outlook is the messaging client of choice for corporate Windows environments.
Messaging vs. Groupware
For the majority of users, Outlook remains a personal information manager rather
than a groupware client. Recent statistics from Radicati Group analysts on the
number of corporate clients using Outlook (489 million) versus the number of
Exchange seats (127 million) suggest how few organizations actually take advantage
of the groupware functionality of Outlook and Exchange. Public folders, calendar
sharing and resource scheduling all require Outlook to be operating in Workgroup
mode, which means an Exchange server on the back end.
Of those 127 million Exchange seats, the actual groupware usage varies dramatically
among organizations. Some firms take advantage of little more than Exchange's
Global Address Book, while others rely on complex solutions based on custom
Outlook forms and server-side events. Those with extensive groupware customizations
will find the transition to open source more difficult and, in some cases, impossible
without a complete redesign of the application.
The Cost of Connecting Outlook
Outlook connectors don't come cheap. The SKYRiX
ZideLook connector costs $65 per user, according to SKYRiX's
Web site. Netline's
OXLook, when bundled with SuSE Linux Openexchange, costs $1,319
for 10 seats. Bynari's
Insight Connector is significantly cheaper than ZideLook and OXLook—$439
for 10 users, including the server.
Even for domains that use Exchange primarily as a messaging server rather than
as a groupware platform, implementing an open source solution requires careful
planning for a successful migration. Companies such as Binary Tree offer products
and services for moving an Exchange store to an open source server. Evaluating
one of these solutions is a good idea when considering a migration.
OpenGroupware.org vs. Open-Xchange
The distinction between groupware and messaging mirrors the difference between
the two most mature open source groupware solutions suitable for replacing an
Exchange environment, OpenGroupware.org and Open-Xchange. The products share
similar lineages. Both originated in Germany as closed-source groupware solutions
running on Linux. Both developers (SKYRiX for OpenGroupware.org and Netline
for Open-Xchange) subsequently donated the code base to the open source community
while retaining proprietary Outlook connectors as a revenue source. OpenGroupware.org
focuses purely on groupware solutions, leaving messaging to other parties. Open-Xchange
incorporates both messaging and groupware into a single package.
OpenGroupware.org and Open-Xchange are by no means the only open source groupware
solutions, but they're the most viable Exchange replacements because of the
availability of corporate support and active development communities. Open-Xchange
remains the most popular corporate groupware package, largely because of its
historical association with SuSE Linux, which was acquired by Novell in January
2004. SuSE, Europe's most popular Linux distribution, has offered Open-Xchange
under the name Openexchange as an Exchange alternative since 2001 under license
from Netline. Since Novell acquired SuSE, Netline open-sourced the majority
of the Open-Xchange server code in August 2004 and now offers both free and
licensed versions. The critical distinction between the versions is the inclusion
of a proprietary Outlook connector (Netline's OXLook connector), installation
tools and product support.
OpenGroupware.org may lack integrated messaging services but it does include
SKYRiX's SOPE application server, which includes 16 packages and 1,500 classes
handling XML, MIME, IMAP4, LDAP, RDBMS and iCalendar. Many of the underlying
components of OpenGroupware.org are identical to those in Open-Xchange. Still,
administrators considering the development of custom groupware applications
need to carefully examine the relative advantages of each product as a platform.
OpenGroupware.org project leader Gary Frederick described the project as "an
Exchange take-out" when the SKYRiX code was open-sourced in July 2003. But OpenGroupware.org
by itself is not an Exchange replacement due to the lack of a messaging server.
OpenGroupware.org can be installed as a groupware component over an Open-Xchange
server or it can interoperate with pre-existing messaging servers.
Developing Open Source Groupware
Both OpenGroupware.org and Open-Xchange provide extensive libraries for the
development of groupware applications. Developers considering adapting groupware
based on Outlook and Exchange must keep in mind that with open source groupware,
much of the code will be on the server instead of the client. An Outlook/Exchange
groupware solution usually consists of customized Outlook forms with VBScript
event code, VBA modules for application-level events and C++ add-ins for radical
customization and low-level messaging programming. An open source groupware
solution that demands programmatic business logic will generally require a Web
interface because of the lack of a client-side application library comparable
to Outlook's Messaging API.
Although the code for Open-Xchange and OpenGroupware.org is publicly available,
learning how to customize or manipulate the software is an uphill climb, especially
for those used to MSDN documentation. The core of knowledgeable open source
groupware developers is significantly smaller than for Exchange, and the solution
for many issues is determined through trial and error. That being said, the
underlying components of open source groupware are established open source services
such as Postfix (a mail transport agent for handling routing and delivery of
e-mail), Cyrus IMAPD (an IMAP4 mailbox store), OpenLDAP (LDAP authentication),
PostGreSQL (database) and Apache (Web). Organizations already using Apache and
Postfix for Web and messaging services have an advantage when considering open
source groupware packages because existing infrastructure can be used as the
base for a groupware installation.
The Next Generation
While OpenGroupware.org and Open-Xchange are the most mature open source groupware
solutions, projects such as the Kolab Server and the Chandler and Sunbird personal
information manager applications could have a significant role in the future
of open source groupware. The Kolab server is associated with the KDE desktop
on Linux, an alternative to the Gnome desktop that the Novell Evolution client
is based on. Although Kolab will interoperate with a variety of clients, Kontact,
the personal information manager for KDE, is the target client application.
The roadmap for Kolab suggests a groupware solution designed for advanced client-server
integration comparable to Outlook and Exchange.
Why Outlook Is So Hard To Connect To
Outlook communicates with Exchange through TNEF (transport
neutral encapsulation format), a method to pass text, files and objects
as well as binary message data that contains Microsoft Messaging API
(MAPI) properties. Any genuine MAPI provider for Outlook needs to be
able to create and interpret TNEF data. This is not a trivial task,
especially considering the high number of undocumented features in the
MAPI object model (160 and counting).
The Chandler project by the Open Source Applications Foundation, while very
much in alpha, is a cross-platform (Mac OS X, Windows, Linux) open source personal
information manager that could be a future Outlook competitor. If Chandler matures
into a full-featured groupware client while remaining platform agnostic, it
could be a viable Outlook replacement on the Windows desktop with a seamless
migration path to an open source desktop. Mozilla's Sunbird project is equally
exciting, if only slightly more mature than Chandler. Sunbird is a calendar
extension for Thunderbird, the mail client that uses the Firefox browser. What
makes Sunbird interesting is that it's based on Mozilla's XUL language, which
allows for the development of stand-alone applications far more functional than
traditional browser-based interfaces. As with Chandler, the option of running
Sunbird on a variety of platforms also provides greater flexibility for administrators.
Active Directory Considerations
Perhaps more than any other Microsoft product, post-5.5 versions of Exchange
rely on AD integration. Replicating some features of Exchange without AD is
nearly impossible. Take the Global Address List and Public Folder permissions,
for example; no existing open source solution comprehensively replicates these
functions. Managing open source groupware permissions is a completely separate
process from managing domain permissions. For an organization with 25 people,
independently re-establishing directory permissions is a manageable annoyance.
For an enterprise with thousands of users, it presents a logistical nightmare.
But for those still on Exchange 5.5, the lack of AD integration isn't a concern,
and may even be a benefit of an open source groupware solution.
Worth a Look
With a planned Windows port of Novell's Evolution and the rapid development
of Sunbird and Chandler, the availability of an open source client capable of
providing functionality comparable to Outlook seems imminent. The Outlook connector
serves best as a temporary measure for open source groupware, a way of leveraging
existing Windows desktops with a mature closed-source client as an entry point
for open source. For Exchange administrators considering any messaging or groupware
upgrade or migration, open source groupware deserves a look. With Windows-based
open source client alternatives to Outlook not yet fully baked, open source
groupware will remain an unfeasible work in progress for some; others will find
the possibilities of server-side groupware carry enough immediate benefit to
replace an Exchange installation.