BEA and Borland are developing a BEA WebLogic Edition of Borland's JBuilder integrated development environment (IDE).
BEA's need for a strong IDE to compete with other application server providers' products was a big driver for the development, which is due for release in mid-September.
Although UK pricing has not been finalised the toolkit is expected to cost about £2,900.
The two companies will also work together on further integration. For instance they will both push the proposed Java web services standard. WebLogic Workshop was the first product to support the standard, with JBuilder following soon after.
Nigel Brown, Borland's vice president and UK general manager, said: "We have common enemies and a common goal.
"BEA wants to remain the number one application server and Borland the number one IDE. IBM's Eclipse IDE absolutely locks you into IBM WebSphere, and Oracle JDeveloper has proprietary hooks into Oracle 9i AS.
"The big advantage is that JBuilder has been the de facto Java development tool for WebLogic, and customers are aware of the benefits of class-leading products.
"If you work purely in WebLogic you can use Workshop alone, but users do not want lock-in."
Neil Ward-Dutton, research director at analyst Ovum, said: "BEA needs this more than Borland. It has had a co-development agreement for some time."
But he added that Microsoft is streets ahead with web services specifications. The Java providers had a lot of catching up to do, he said.
However, BEA and Borland are talking up the new software. "We believe that JBuilder WebLogic Edition will become the pre-eminent development solution in the market," said Dale Fuller, Borland's chief executive and president, in a statement.
Both companies will sell JBuilder WebLogic Edition through their existing reseller channels as well as making joint bids to key customer accounts.
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