Isobel is a framework to build complex information retrieval and analysis systems. Isobel can be functionally divided in two subsytems, Isobel Gatherer (the crawling and filtering subsystem) and Isobel Analyzer (the analysis subsystem). The two subsytems can also be used separately. Isobel Gatherer offers ready-to-use services like content fetching, scheduling, document format conversion, Hyperlink graph storage and analysis, content storage and indexing. A programmer may easily add new services. Isobel Analyzer uses the IBM UIMA architecture to reuse the analysis components developed for this architecture.
Augmented Syntax Diagrams (ASDs) provide a way to represent grammars of natural languages as directed graphs. Nodes represent instances (or usages) of words and phrase types in a language such as English. Edges link nodes together to indicate how instances of words and phrase types can follow one another to make up phrases, clauses, and sentences in the language.