The fight between IBM and Microsoft Corp. for development environment supremacy is heating up about as fast as the onset of summer, with both sides digging in for a showdown, although IBM appears willing to make a concession.

At the IBM Rational Software Development Conference here two weeks ago, IBM ratcheted up the battle a notch by introducing technology to help the Armonk, N.Y., systems company integrate its solutions for business, application development and IT operations, something Microsoft has been trying to do and is expecting to deliver with Visual Studio 2005 and the Dynamic Systems Initiative.

IBM's plan, like Microsoft's, includes heavy use of modeling technology to enable business analysts to essentially define models for applications and then have tools generate code to produce applications that will, through the use of automated tools, be more easily monitored and maintained by IT operations.

In fact, IBM demonstrated this capability at RSDC when Grant Larsen, a model-driven development strategist for IBM Rational, showed what he called Solution Guides, or recipes for building solutions for various industries such as retail or insurance, in a demo using IBM technology available now.

Meanwhile, Microsoft is promising to deliver competitive technology when it releases its Visual Studio Team System later this year. Microsoft will likely heat up the debate around VSTS at its Tech Ed conference in Orlando, Fla., this week.

Despite early discussions regarding continued support for Microsoft and its .Net platform when IBM initially acquired Rational Software Corp. in 2003, IBM now seems to be pulling back from the pledges that Mike Devlin, the co-founder and former general manager of Rational, and Steve Mills, head of IBM Software Group, made following the acquisition that IBM would continue to provide deep support for .Net.

"I don't think it's a matter of pulling away," said Danny Sabbah, the newly appointed general manager of IBM Rational. "You have to be careful because Rational never had a significant presence in terms of the core integrated development environments that developers use every day. After the acquisition by IBM, all of a sudden Rational inherited an end-to-end life-cycle capability that not only dealt with methodology and process but also dealt with all aspects of integrated development. Microsoft saw that as a threat and so all of a sudden moved to provide that capability."

Moreover, Sabbah said Microsoft is in the midst of a transition in terms of overall programming models with "Longhorn" and "Whidbey." With that in mind, IBM demonstrated integrating some of its software life-cycle tools such as Rational ClearCase and Rational ClearQuest with Whidbey. But, across the board, support is not in the cards, Sabbah said.

Read more here about how IBM is wooing prospective developers.

Meanwhile, IBM last week reiterated that its primary weapon in the battle for tools supremacy will be the open-source Eclipse-based tool set, while Microsoft is backing its proprietary .Net-based VSTS.

"This again comes back to the customer, and lots of customers are heterogeneous," said Lee Nackman, vice president of product development and customer support at IBM Rational. "Is Microsoft going to give customers artifacts for developing on cross-platform systems?"

One customer, Aniello Bove, director of development environments at UBS AG in Zurich, Switzerland, said his organization is heavily into SOAs (service-oriented architectures). "Our new platform is based on SOA, and we're using model-driven development" and the Object Management Group Inc.'s Model Driven Architecture and UML (Unified Modeling Language) specifications, Bove said. Partly for that reason, UBS has decided to go with IBM's development option, as Microsoft is not outwardly supporting the OMG specifications. "We decided what our architecture looks like, and there is no .Net development," Bove said.

This article was originally published on eWEEK.com.