Benefits of an Extensible Platform
The UI components of OpenII are based on the open-source Eclipse platform. As a result, new OpenII tools can easily be added to the platform. Moreover, the existing OpenII tools rely on public interfaces, which allow the tools to be customized or extended. For example, developers can easily add new matching algorithms to Harmony or add new distance metrics to Affinity. Behind the scenes, the various tools communicate via Java events, or via a Yggdrasil, a shared repository.
What is Yggdrasil?
In mythology, Yggdrasil is the tree that connects all of the worlds. In OpenII, Yggdrasil is the repository that connects all of the tools in the OpenII platform. The repository is based on a neutral metamodel, allowing the repository to store both mappings and schemata expressed using various formalisms (XML schemata, relataional database schemata, RDF ontologies, etc.).
Benefits of a neutral metamodel
First, any OpenII tool that interacts with the repository can automatically handle any data model for which an importer exists. Thus, OpenII avoids becoming a suite of tools for a specific modelling language. Second, new modelling languages can be supported by creating an importer for loading new data models into the repository.