Linux is taking the world of Java application servers by storm. Recently, Sun Microsystems hosted an event to tout the adoption of the latest version of the enterprise Java platform, known as Java 2 platform, Enterprise Edition, or simply J2EE 1.4. At this event, many of the application server vendors were present. Nearly all of them said Linux is making huge gains as the platform of choice for developing and deploying enterprise Java applications.

The event featured a panel with well-known application server vendors IBM, BEA, Oracle, JBoss, and Sun. It also included smaller vendors Trifork and Pramati. The panel covered a wide array of topics, from open source to Web services to Linux.

When the subject of Linux came up, the vendors uniformly agreed that Linux was a fast-growing platform, and very important to their respective businesses. IBM WebSphere product executive Mark Heid proclaimed "Linux is the dead-center of our strategy." IBM's WebSphere application server does provide support for a wide array of Linux platforms including Red Hat, United Linux, and Red Flag Linux, the Chinese-government sanctioned version of the operating system.

Mike McHugh, vice president of engineering, WebLogic Platform, BEA, said that Linux was the application server vendor's fastest-growing platform. He also suggested that enterprises are shaking off their past reticence to develop and deploy on Linux. "Customers are pulling it," said McHugh, suggesting that enterprise IT environments may be ahead of vendors in their support and adoption of Linux.

Even Sun, who has been pushing Solaris x86 hard recently, said that Linux was the second most popular download, after Windows. "We see it as a huge part of our market," said Jeff Jackson, Sun's vice president of engineering for J2EE. He indicated Sun has seen more than 1 million downloads of the Linux version of its latest application server release. While downloads do not equate to actual usage of product, this does suggest popularity of Linux by users of Java on servers. This also calls out a shift in demand for a company that makes the lion's share of its revenue on Solaris-based servers.

Unabashed support for Linux was not universal. Marc Fleury, controversial CEO of the open source application server JBoss, opined that Linux has had a secondary effect on JBoss's business. "Our business isn't really affected much by Linux directly, although we believe it has paved the way for open source and actually accelerated adoption of JBoss," said Fleury. Other vendors said the Java platform insulates them from Linux. "What is under the application server is abstracted away from the Java developer," said Bill Pataky, senior director in Borland's tools division.

The participants were in agreement that the most important innovation of the latest release of J2EE was the inclusion of Web services. "I think the inclusion of Web services is the most exciting thing about [J2EE]1.4," said Jackson. The latest release of J2EE also includes requirements for conformance to Web services standards from the WS-I organization. This was done for more than technical reasons. "Standards compliance is a big cost-saver," said Vijay Pullur, CEO of Indian application server vendor Pramati.

The most controversial exchange of the event was over the topic of open sourcing Java. IBM recently sent an open letter to Sun suggesting the two companies work together on this topic. JBoss's Fleury was characteristically direct on this issue. "Don't do it, Sun. It's a trap," Fleury said, suggesting it was a ploy by other companies to wrest control of Java from Sun. Most of the other panelists suggested that open source would be good for Java, and parallels were drawn to the Eclipse project.

Sun CEO Scott McNealy angrily dismissed the notion of open sourcing Java at an industry event. But Sun's Jackson was a bit more conciliatory. "Open source has been good for Sun." He also added that an open source Java specification would still have to go through the Java Community Process, the standards approval mechanism for the Java platform. The fact that these two messages are at odds indicates that the debate over the future of Java and its source code is far from over.

Adding to the maelstrom of confusion at Sun is its slipping OS market share, most of which is directly attributable to Linux. "We see more development desktops on Linux than on Solaris," said Pataky. Borland makes one of the leading Java IDEs, JBuilder. Java may be Sun's unintentional way of shooting itself in the foot, making one of its crown jewels, the Solaris operating system, irrelevant. "Our deployment platforms are application servers, not operating systems," said Pataky, indicating that it is Java and J2EE that are important, not the operating system. This could spell big trouble for the hardware vendor whose revenue is still directly tied to making servers and operating systems, and raises some interesting questions about Linux as well.