What is notable about using XMPP is that you can separate the messaging and presence functionality if desired (although most deployments offer both). This comes in handy when building application-to-application messaging systems that don't involve users typing text messages to each other, such as a server sending an alert when it detects a problem to a network operator. Currently, there are more than 30 active projects to extend IM into bookmarks, delayed messaging and other areas.

Go with Jabber and its ilk if you want to build your own IM applications, or don't want to spend the cash on a Lotus or Microsoft offering.

The world of IM is rapidly changing, as last week's announcements from Microsoft and AOL have shown. Expect the innovations to continue. But if you haven't gotten on board the IM train, you should consider starting a pilot project with at least one of the three strategies mentioned here.

David Strom is a writer, editor, public speaker, blogging coach and consultant. He is a former editor in chief of Network Computing and Tom's Hardware and has his own blog at http://strominator.com. He can be reached at david@strom.com.