Codenamed Atlantic, and promised for release by the end of this year, IBM Rational’s beta client and server suite is being used by customers under a non-public program, according to a company spokesperson.

Atlantic will see XDE, IBM Rational’s Unified Modeling Language (UML) tool for WebSphere and Microsoft Corp’s Visual Studio.NET, disappear as modeling becomes a feature of IBM’s WebSphere Studio Application Developer (WSAD) under Atlantic.

XDE was launched by Rational Software Corp in February 2002 as eXtended Design Environment. XDE provided a window that enabled UML-based modeling inside the IDE itself, narrowing the gap between application design and build.

IBM Rational refused to comment on what it called rumors.

However, Meta Group analyst Tom Murphy said it was an inevitable step, to bring together a complete collaboration environmen by merging XDE and WSAD.

People need an environment that helps the different team members to collaborate better together. This puts them [IBM Rational] in a better position than [other Java 2 Enterprise Edition (J2EE) tools vendors, said Murphy.

IBM Rational’s decision to merge XDE’s modeling capabilities with the WSAD comes as vendors attempt to tackle the question of how to improve application development. Companies are trying to improve communication and collaboration between Application Lifecycle Management (ALM) team members in order to produce applications that meet business requirements and that are also easy to manage.

Microsoft will next year move into ALM with Visual Studio 2005 Team System (VSTS), which combines modeling, development and team-based collaborating.

IBM Rational’s decision to phase-out XDE, though, raises a question over the business unit’s continued long-term support for Microsoft’s .NET and Visual Studio. At the time of IBM’s acquisition, Rational committed continued support to Microsoft, however, IBM Rational’s ALM competitor Borland Software Corp. noted its relationship with Microsoft improved noticeably in the wake of IBM’s 2002 purchase.

Murphy said folding XDE into WSAD raised the question of whether IBM would supply dual products, one set for Java and another for .NET. He noted, too, there is some posturing taking place between IBM and Microsoft, with the companies painting similar ALM visions of integration through their respective platforms.

Both companies are also aiming for broadly similar release dates. Microsoft has promised VSTS for the first half of 2005, with IBM due this year. However, it has been unclear whether IBM Rational was on track to hit its deadline, as there had been no word on betas.

There’s some posturing with Microsoft over who comes out first, said Murphy .