This article by John Waters of explores the current status of the application server in the corp IT infrastructure, the market players, and where its future is heading. Some interesting extracts: a handful of market-dominating vendors are doing more than just fattening a hunk of middleware with features. They are, some analysts believe, spawning a new species of app server. ... ''A lot of people are looking at the app server market today and asking, is the app server getting bigger, or evolving into something else?'' said Eric Stahl, director of product marketing at BEA Systems. ... Analysts agree that the surviving app server vendors are adding features and functionality primarily to differentiate themselves in a competitive marketplace. But Bob Sutor, director of IBM's WebSphere software group, said the changing role of the application server is also inextricably linked to the advent of Web services and the rise of service-oriented architectures. ... ''We no longer think of the application server as one big monolithic application,'' he said. ''It is being pulled apart into the major areas that we think of as functions.'' [Sutor] ... ''I don't see the current set of players going away,'' said Neil Macehiter, an analyst with London-based market research firm Ovum. ''BEA, IBM and Microsoft, because they are so dominant; Oracle and SAP because they have the customer base. The one unknown is Sun.'' ... The other wildcard in the app server space is JBoss, a popular open-source implementation of J2EE, which is available free under the LGPL license. This application server is supported commercially by The JBoss Group, which provides consulting and implementation services to users. ... ''The vendor community is saying that it's J2EE vs. .NET,'' Macehiter said, ''but the reality is that, more often than not, the two co-exist in an organization, so that becomes less of a real issue. The decision here is much more about the skills an organization has in-house in terms of application development, and its investment in application development solutions, rather than whether it's J2EE or .NET.'' ... Perhaps more important today than the smoldering Java-Microsoft platform wars, said Forrester's Rymer, is the issue of complexity. ... A Giga Information Group report published last year noted that the app server market had declined a bit (from between $2.3 billion and $3.1 billion in 2001 to between $2 billion and $2.8 billion in 2002), but Giga (now Forrester) and most analysts expect the market to grow over the next few years. Ovum has estimated that the app server market will be worth $17 billion worldwide by 2004. Read.