While UML is very effective at modeling software systems, it is deficient in its ability to help practitioners understand how software systems interact -- this is where the software fortress model picks up. The vendor-independent software fortress model treats enterprise systems as a series of self-contained software fortresses. Each fortress makes its own choices as to software platform and data storage mechanisms, and interacts with other fortresses through carefully crafted treaties. This unique approach simplifies the enterprise. It helps the software professional truly understand how systems interact. This book defines, clarifies, and explains the basics of software fortresses. The author believes this new approach will grow in popularity and evolve over time, and this book will be the genesis of a popular enterprise development movement.