Sun rolled out two lower-end editions of Sun One Application Server Version 7 late last year. At the time the company said it aimed to deliver the enterprise edition by the first quarter of this year.
The product adds features considered important for some enterprise applications, including a clustering technology acquired from Clustra Systems.
The enterprise release was not among the products on tap for this quarter, a Sun official at this week's event declined to offer a new release date. Information on Sun's website set the product for release in "summer 2003".
"We're very interested in making sure the product hits the market well, said Anil Gadre, vice president, Sun software business management and marketing.
"The first experience developers have with it must be a really good one, so for the sake of ensuring quality or performance we'll say, do you make a date or do you take a few more weeks to get it right?"
Gadre would not offer details about what might be holding up the release but said Sun may distribute an "early access" version in the next few months. He said customers in general have responded well to the new application server and that the platform and standard editions are "getting good traction".
Application servers provide a platform for deploying applications such as e-commerce software, and for distributing data to a variety of client devices or building portals. Sun is among the smaller players in the market battling for share against leaders BEA Systems and IBM.
A delay of a few months should not be of great concern, said Forrester Research analyst John Rymer. After Jonathan Schwartz took charge of Sun's software group last year it underwent a reorganisation that put it in "a state of flux".
"It seems there was a fairly substantial reorganisation and it took the wind out of their sails on the momentum of some products, as these things usually do," he said.
Schwartz suggested Sun's Orion initiative, through which its various software groups are adjusting their product release cycles to a regular, quarterly schedule, could be another factor. The program should, eventually, benefit customers by supplying them with a more tightly integrated set of products but he warned that in the short term there may be teething problems.
"I expect all the groups to hit some bumps in the road as they fall into line with that program," he added.
The application server is not the only Sun One product to have fallen behind schedule. Last month it released a package of middleware and tools for developers called the Sun One Web Services Platform Developer Edition. That product was originally scheduled for release late last year.