TAIGA (Twente Advanced Interactive Graphic Authoring system) is a system which can be used to develop instructional software. It is written in MS-PASCAL, and runs on computers that support MS-DOS. Designed to support the production of structured software, TAIGA has a hierarchical structure of three layers, each with a specific function, and each layer is supported by an editor. Level 1 involves the structuring of course contents with a module editor; Level 2 includes the structuring of instructional interactions with an episode editor; and Level 3 provides for the specification of course contents with a text/graphics editor. The system also includes a facility that allows external programs to be incorporated into the courseware, thus permitting experienced programmers to implement simulation and gaming courseware. TAIGA consists of four main subsystems: (1) Copro, a production subsystem which is used to create and edit the courseware; (2) Codis, the distribution subsystem which is used by students to access the courseware; (3) Comas, which is used to supervise access to other subsystems and perform elementary database functions; and (4) Coeva, which accesses the student log file produced by Codis, and produces summaries for evaluation purposes. Several utilities are also available, including Codoc, which produces a listing of the courseware. A detailed description of the functioning of the system includes examples of menu screens. Several diagrams are included as well as information on hardware requirements and how to obtain a copy of the software. (EW)