Would you like to write software that can adapt to the user, learn from examples or work with uncertain information? Infer.NET is a machine learning framework that lets you build these capabilities directly into your .NET application. The framework allows you to combine detailed domain knowledge with the latest machine learning algorithms to generate tailored code to solve your problem. An API based on random variables lets you call Infer.NET code from within your application. We provide examples of using Infer.NET in search and gaming.