Schematic representation of the main BioWord control flow (bold blue arrows) and the interplay between classes and modules (black arrows). Classes are represented by rounded boxes and modules through squared boxes. The design structure is geared to decouple the basic classes (Sequence and ColSequences) from the Microsoft Word interface. A normal workflow starts with the user making a selection on the document and clicking one of the buttons on the BioWord ribbon. The RibbonControl module captures the click, parses the user selection, instantiates a ColSequences object and calls the appropriate ColSequences method. Control returns to the RibbonControl module upon completion of the required processing, and a call is made to the Resources module to implement the output process.