About the authors BRAN SELIC is Vice President of Research and Development at ObjecTime Limited, a Canadian company that develops and markets a toolset (ObjecTime) supporting ROOM. He has over twenty years of design and project management experience in real-time software development covering a range of applications including telecommunications, aerospace, and robotics. GARTH GULLEKSON is Vice President of Marketing for ObjecTime Limited. He worked for Bell Northern Research for fourteen years, primarily in the design and management of real-time telecommunications software. PAUL T. WARD is a principal of Paul Ward & Associates (formerly known as Software Development Concepts), a New York City firm providing training and consulting for real-time systems developers. In collaboration with ObjecTime Limited, Dr. Ward provides customized courses on ROOM and ObjecTime. He is codeveloper of the Ward-Mellor approach and coauthor of Structured Development for Real-Time Systems - a standard text for software engineers.