BDE is a Block Diagram Editor. The purpose of BDE is to capture the semantics of software design diagrams that support various CASE tools and track design changes. BDE is also used to construct Structured diagrams and Data Flow diagrams. It maintains Persistent Diagram Database.

BDE has certain Graphic features as to use only one button of mouse, to draw nodes of various shapes, to connect nodes by edges or links, move or resize nodes or captions, maintain node-link connections, split links into multiple segments and also to change link segment drawing style. In the same way it also has Text Features like creating text captions in diagrams, attaching text attribute lists to nodes, to attach text label lists to links, delete and relative-move text lines, to update any text line and Lexically parse and tokenize text.

BDE also has few Persistent Data Features like storing multiple diagrams in a file, to save diagrams as PS, convert diagrams to GIF.

BDE2java is a Java based Block Diagram Editor application which runs as an applet allowing user to construct Data flow diagrams, Structured diagrams and State Transition diagrams etc..,