Each product had at least one feature we wished the other offerings had. For example, only Jabber's Extensible Communications Platform (XCP) informs a user when he or she is being added to someone else's contact list. Jabber's IM product doesn't have polling, but IBM Lotus Instant Messaging does. The IBM product doesn't have news boards, but Sun's ONE Portal Server: Instant Collaboration Pack offers this feature.
Each vendor also takes a different approach to implementing the client software. Most products require a Windows executable or a Java applet, but Sun and WiredRed offer a stripped-down client that requires only JavaScript. Sun's full client is a Web applet, and WiredRed uses a Win32 executable. Gordano's full client also requires JavaScript only. IBM uses the Microsoft Java virtual machine for advanced messaging (such as screen sharing and whiteboard usage). Jabber's product includes a Java-based Web client and a Win32 executable. Only Ipswitch and Microsoft don't offer browser-enabled IM capabilities. Surprisingly, even on meager 600-MHz client machines, the Java Web interfaces performed as speedily as their Win32 counterparts did.
All the products use their own message formats except for Jabber's, which uses XMPP (Extensible Messaging and Presence Protocol), an open standard. Some of the products can speak multiple protocols. For example, we used the IBM Lotus Instant Messaging client to access the IBM server and AIM simultaneously.
Remote users will also need some way to communicate with internal users. A VPN tunnel will let you bypass many firewall issues; otherwise you may need to open a few firewall ports. And you'll want to prevent your employees from reading your CEO's IM. Fortunately, all the products support message encryption.
The server side requires surprisingly little management. The Sun, Gordano, Microsoft and Ipswitch IM components have no management interfaces. The Sun ONE Portal Server lets an administrator log in via IM and assign management rights to other users, but this is done on the client side. Likewise, IBM Lotus Instant Messaging lets users assign the moderator and access controls for their own created chat rooms, but a management interface creates permanent or predefined conferences and viewing log files.