IBM's Domino, and Microsoft Exchange are the two big names in this field, with Novell Groupwise right behind them. These 800-pound gorillas have everything you need, but the flip side is the high costs of installation, and the need for experienced people to keep everything running smoothly.
Here's where Open-Xchange Server comes in. If the name is unfamiliar, it may be because the project has had a chequered past. Originally developed by Netline, and then as SUSE Open Exchange, the project was spun off by Novell after it purchased SUSE, and the core source code was released under the GPL. A commercial version is available for those who want to have an easy installation, service, and support, and automatic updates. If you have the necessary experience, you can download and install the free version as well at www.open-xchange.org. The user community has written several guides to help you with installation, which are available on the wiki.
I tested the commercial version of Open-Xchange 5 through a handy live CD. This is freely downloadable, and since it's based on Knoppix, it runs on pretty much any computer. The live CD lets you try out the various features of Open-Xchange, and helps you decide if you want the full package.
The commercial version of Open-Xchange can only be installed on either SUSE Linux Enterprise Server 9 or Red Hat Enterprise Linux 4, along with a Binary Disc update. By narrowing down the options, the developers are able to avoid a lot of distribution-specific caveats. The free version can be installed on pretty much any GNU/Linux distro, but you won't get the nice Web-based administration tools or any free technical support. It is possible to pay for support, however.
Features and accessibility
Open-Xchange has all the necessary groupware features and then some, including email, Web mail, group and individual calendering, a searchable knowledge base, and robust document sharing capabilities. The document sharing feature has automatic versioning and file locking, which are useful when you have different people working on the same document. The knowledge base is useful as a central repository of information, such as company policies, or software manuals.
Accessibility remains the single most important aspect of a groupware suite. It must be easy to use, and provide information to every sort of user, whether they be geeks or absolute technophobes. If the interface is complex and confusing, your employees may forgo using it. The Open-Xchange interface is clean and simple, and most people shouldn't have a problem with it.
Open-Xchange supports all major browsers, including Firefox, Opera, Mozilla, and of course Internet Explorer. If your users are accustomed to Microsoft Outlook, you can use the Outlook-OXtender to seamlessly use the Open-Xchange server. I tried out both, and though I preferred the Web-based interface, I didn't have any problems with the Outlook-OXtender. I didn't see any rendering problems or interface flakiness in any of these browsers.
The Open-Xchange calendar has the ability to determine availability windows, send email invitations, and link to relevant documents. None of these features are new, of course, but they are essential, and fairly well implemented. All the standard calendering features are also present.
Document sharing is an interesting feature in Open-Xchange. Since it supports automatic versioning and file locking, you can have multiple people working on the same document, and easily track changes in the document. Microsoft also supports this in the newer versions of Office, but Open-Xchange works just as well with other software, including OpenOffice.org.
The portal can be customized to some extent by individual users to suit their preferences. Also, the administrator can customize the look of the entire product by tinkering with stylesheets, which isn't extraordinarily complex. You can change colours, add your company's logo, and generally make it look the way you want.
The rest of the groupware features are similarly well implemented -- nothing extremely fancy, just simple and easy to use. The Contacts, Webmail, Project Management, and Document Sharing screens all work as expected.
If you are thinking of migrating from Microsoft Exchange, Open-Xchange, Inc., and its partners provide some help. It may not be an easy job, however, so do your research before you take the plunge. On the other hand, if you are setting up your groupware application for the first time, Open-Xchange is especially attractive.
I wasn't able to stress-test Open-Xchange Server with large user loads, but given that it's based on extremely scalable open source software such as Postfix, OpenLDAP, Apache, Cyrus IMAP, Tomcat, and PostgreSQL, it should be able to scale fairly well. Both SLES 9 and RHEL 4 are likewise used in large corporations, so the structure looks fairly sound. Of course, extensive stress-testing before you use any product in a production environment is always a good idea.
Open-Xchange's Web-based administration tools are easy to use. You have a basic tree menu on the left, with just six headings: User, Groups, Resources, Resource Groups, Mailserver, and Security. They are fairly self-explanatory, and don't have an overwhelming number of options. You can add additional modules to Open-Xchange, as and when you need them. The administration can be handled by someone who is reasonable competent; you don't need a full-time Linux geek to keep it all running.
You can set up groups of users and give them access to distinct functions. You can easily restrict access, move people around in groups, and generally micromanage your users' permissions to view things.
The administration may be simple to the point of being too simple. Some businesses may find that they have specific requirements that are not addressed in the base package. Banks and financial institutions may need higher security, for example. Open-Xchange is expandable, and since it is based on widely used standards, you should be able to find people who can easily modify it. The source code of the base is freely available, but the administration interface is proprietary.
As an administrator, it is important to note that you cannot change the basic software required. If you don't like PostgreSQL or Cyrus, too bad. However, there is no real reason to get under the hood, with two exceptions -- anti-virus and anti-spam.
Open-Xchange offers no anti-virus program support out of the box. It is possible to set up ClamAV with Postfix, but you'll have to get your hands dirty to do this. Spam filtering is included, but again, to set it up to your liking, you'll have to edit the config files. These two omissions struck me as being slightly odd, given the amount of havoc spam and viruses can cause.
Drawbacks and conclusion
The biggest problem with Open-Xchange is the restriction on installing only on SLES 9 or RHEL 4. There are many small to medium enterprises that are running one of the RHEL clones, such as Centos 4, or a Debian-based distro, and forcing them to buy an expensive enterprise version seems a little excessive. This is one of the most common complaints on the Open-Xchange user forums. The GPL version can be installed on any *nix distro, but it doesn't have the slick interface or the usability of the commercial version.
Since even proprietary enterprise applications such as Oracle can run just fine on the RHEL clones, and Open-Xchange is based on open source software, there doesn't seem to be any technical reason why it should be restricted to running on just these two distributions. It seems to be more of a policy matter, rather then a technical reason. I asked Open-Xchange about this, and got a predictable answer, stating that they "want to link the users of our commercial product to a commercial vendor that _guarantees_ the maintenance for the operating system." To be fair, they do have a point. I still feel that they could have released a stand-alone version, but your opinion may differ.
The lack of an integrated anti-virus and anti-spam solution is another drawback. The developers should consider integrating Clam-AV or a similar solution into Open-Xchange. Administrators should be able to manage the spam filters through the Web front end as well.
Open-Xchange is available only in a 32-bit version at the moment, and there is no support for IPv6.
Pricing for Open-Xchange starts at $389 for the Small Business edition with five named users, and goes up to $1,095 for the Advanced Server edition with 25 named users. These prices do not include the cost of RHEL4 or SLES 9; you can buy bundled versions for a few hundred dollars more. If you need support for more users, you can buy additional licenses. The only difference between the Small Business edition and the Advanced Server edition is the limit on the number of users, and support while installing. The SBS edition supports a maximum of 25 users, while the AS edition has no specific limit.
Outlook OXtender and Palm OXtender are included in the price. Open-Xchange also has academic and government price discounts for qualifying institutions.
At the end of the day Open-Xchange comes across as a pretty good product for its price. It will be most attractive to small/medium enterprises that are setting up groupware for the first time. If you are already using a different application, migrating can be difficult.
Open-Xchange works well, has a decent feature set, and is platform-agnostic. It's not perfect, and lacks a few features, but all in all, it gets the job done.