Sophisticated applications involve huge numbers of detailed domain business rules. These rules are the heart of the application, determining critical details such as how much money is transferred between two banks (in a financial application), which compounds have been identified in a sample (in a chemistry application), or how a customer's money should be refunded (in a point-of-sale application). These details, while crucial, are too easy to get wrong. Sometimes, only the business experts can tell when the software is right or wrong. That's where open source Fit can help you. Fit is an automation tool for helping improve communication between business experts and programmers, allowing you to identify miscommunication and prevent business rule defects before they happen. Join James Shore for an introduction to using Fit in your project.