The era of high-end licensing deals for application server's is long gone, but even in an area now nearly perceived as a 'commodity', its always interesting to know who the dominant players are. Rod Johnson blogs about the issue 'Is it a Tomcat, or the Elephant in the Room?'
However, there is little doubt about the leadership of Tomcat, which is consistent in both results. Other analyst firms who are researching the area, such as the 451 Group, are finding similar results. Some interesting takeaways: * IBM's WebSphere is very strong in adoption. We see that in customer accounts. * Tomcat is a clear leader. It may well be the elephant in the room. This is particularly interesting given that no large (or even medium sized) vendor is promoting Tomcat. The Tomcat numbers aren't driven by vendor marketing, but by thousands of companies making similar decisions. * Also from our observations in customer accounts, I would expect that a large part of the JBoss numbers are actually Tomcat. Many users who think they're using JBoss are actually using a less efficient form of Tomcat. One example–the French Tax Office's online taxation service–is a public reference for both JBoss and Spring. Of course, Tomcat is not a complete alternative to WebSphere or WebLogic. It still lacks a number of important enterprise features that those products have, although it is making progress in important areas such as clustering, and its performance is much improved compared to a few years ago. At this point, it's not an apples-to-apples comparison, but more analogous to Oracle vs MySQL.
Read Rod's complete post: http://blog.interface21.com/main/2007/12/24/is-it-a-tomcat-or-the-elephant-in-the-room/