"Oslo" is new modeling framework that is destined to become a centerpiece of modern model-driven development on Microsoft platform. It was officially announced and described in details at PDC2008 and received almost as much attention as Azure Services Platform.

Main goal of model-driven development is increasing developer productivity by building application models first and moving to physical implementation and deployment later. Oslo helps to achieve this goal with its language,  tools and repository. M language, released under Microsoft Open Specification Promise, describes the model textually in domain-specific terms, IntelliPad tool captures the textual description and proofs it against predefined constraints, Quadrant parses M-based DSLs created in IntelliPad, which become WF activities debuggable in Visual Studio, edits their instance data, shows visual representation of the models and relationships and finally stores them in Oslo repository in SQL Server.

Oslo tools themselves are model-based (e.g. everything, including icons and button positions, gets pulled from the repository upon launch) allowing them to be extremely configurable (although completely ISV-customized environment will only be possible in V2); they don't start if the repository database is not available and can be modified right in the database if needed. Even clipboard items in Quadrant are modifiable in the workspace after user pulls them from the repository.  Fetching the entities becomes a snap with LINQ query and extending them is as easy as adding new items to the displayed list. Oslo tools also sport innovative UI with things like free-form workspace and scrollbars displayed with overlay in screen regions (workpads) activated by holding left mouse button.

Oslo ships with many pre-existing models that describe business processes, the structure of composite applications, workflows, service and data contracts, etc. and they are also available in the .NET Framework in the form of XAML.

"Oslo" SDK (October 2008 CTP) is available now on the downloads tab.

More information on "Oslo" modeling platform can be found at "Oslo" Development Center .