While architects and designers often draw up application architecture on white boards or in separate applications, their drawings and the world of software developers often remain isolated.

Traditional modeling tools haven't gone far beyond using the models as a sketch or blueprint that's not connected directly to the code or the development environment. Microsoft intends to take the next step with its Oslo suite of modeling software by making a model into an executable that can be reconciled with code or with other models to make sure the software fits the design, and by making the models accessible in Visual Studio.

"The world is model driven and Oslo is just a toolset to manage a model-driven world," said Robert Wahbe, VP of Microsoft's connected systems division.

Models will eventually make their way out of Visual Studio and into other Microsoft tools like its System Center management suite.

"We want to radically expand what modeling means," said Norman Guadagno, director of product marketing for Visual Studio Team System. "When people say modeling today, they're thinking application development workflow. There's no reason to separate identity, policy, security, and deployment information from the model."

Though it has a big vision with Oslo, Microsoft's starting off fairly small. At October's Professional Developers Conference, Microsoft will release the first test versions of three pieces of its modeling vision that will form a foundational architecture to Microsoft modeling capabilities going forward.

The three pieces include a modeling language, repository, and tools available in test versions as add-ons to Visual Studio by October at this year's Microsoft Professional Developer Conference. They'll see their final releases as parts of the next version of Visual Studio Team System.

During a presentation at Microsoft's TechEd conference Tuesday, Microsoft technical fellow Brian Harry demonstrated new tools called Architecture Explorer and Architecture Layer Diagram that will allow architects and developers to work to make sure code stays in line with architecture guidelines. Architecture Explorer allows architects and developers to visualize application logic in current code, while Architecture Layer Diagram shows what the application logic should look like. The applications also allow developers and architects to validate actual code against the diagram and create a technical policy to validate code before it gets checked into the system.

"You can take an application that you've never worked on before, take a modeling tool to parse that application and show you a model of it, make changes, and make sure it validates against the design," Harry said.

In a later question and answer session, Gates said that Microsoft would begin supporting the standardized Unified Modeling Language for object modeling in Visual Studio 10, which is the next version after the current Visual Studio 2008.

The main competitor for Microsoft will be IBM Rational, which Gartner analyst Nick Gall said hasn't tried to pin on one specific model architecture, as Microsoft will.

According to Gall, the first big test for Oslo will be whether it's simple enough for non-developers and non-PhD architects to use. He said they'll likely pass that test, but there are others looming.

"What they really haven't showed me is proof of the scope of the model or that they can sustain the model over the lifecycle," he said. Think of software as a house, he explains. When it's first built, the blueprint matches well with the house, but after repeated renovations, the blueprint ends up not fitting perfectly with it. It's unclear how Microsoft will account for changing the model mid-development.