Sun has updated its Java Enterprise System, adding support for HP-UX and Windows in the hope it will spur wider adoption.

JES is an integrated suite of more than a dozen middleware components including its application server, directory server and portal server. JES has struggled to gain market share from similar "platform suites" from IBM, BEA and Oracle.

Customers who buy JES Release 3 will also get a license for Sun's Identity Manager, N1 Grid Service Provisioning System, Portal Server Mobile Access and Java Studio Enterprise products, which are typically priced separately, said Deborah Williams, group marketing manager for JES. The products have not been integrated with the suite, like the other components, but are offered separately, she noted.

Also new is the Enterprise Edition of Sun's application server, which supports the latest version of the J2EE spec, as well as some features for improving application availability.

The upgrade has already been released for the Sparc and x86 editions of Solaris, including Solaris 10, and Linux. In four to six weeks it will be available for HP and Windows XP and 2000, Williams said.

Sun sells JES on a subscription basis, with pricing based on an organisation's total employee count. JES Release 2 was $100 per employee per year, with an additional fee for Java Studio Enterprise, Sun's developer suite. JES Release 3 is $140 per employee, including Java Studio Enterprise. It also comes with Java Studio Creator, Sun's free visual development tool.

"We feel the increase in price is justified by the value of these additional products," Williams said. "They are products - especially Identity Manager - that a lot of customers are interested in using."

JES has not been selling quickly of late. In reporting its financial results last week, Sun said its subscriber base for JES increased by just 15,000 in the three months to March, for a total of 433,000 since the suite was launched a little over a year ago.

But analysts are divided over the prospects for Sun's middleware. The company lags behind competitors because it has not made the most of acquisitions and has done a poor job marketing its products, according to Henry Pyret, an analyst with Forrester who said he does not know any JES customers. Sun has not been seen as a leader in the trend towards converging products for developing and integrating applications and building portals, he said. And middleware products from its rivals have supported Windows and HP-UX for a long time. "It's a little bit disappointing the way they are managing their software," he said.

James Governor, principal analyst with RedMonk, was more upbeat. Sun's pricing model for JES is relatively new and the company is still figuring out the best way to price and package its products, he said. Sun may yet be able to capitalise on the strength of Solaris to sell more infrastructure software, he said. "They were coming from a negative perception, but from a product standpoint they are increasingly seen as good enough," he said.