The .NET Framework is a “managed” platform: programs and libraries are compiled to bytecode (MSIL), and loaded and executed on the Common Language Runtime, which JIT-compiles that bytecode to native machine code (and provides other runtime features, like garbage collection). That’s great for some kinds of application, but it makes shipping and deploying your code complicated; you either need the target machine to have .NET pre-installed, or you have to ship the entire runtime and all dependencies along with your app.
CoreRT offers a solution: it takes the bytecode and compiles it to native machine code Ahead of Time (AoT), including the runtime and dependencies. You end up with a single executable file that starts quickly and has no dependencies. CoreRT is still in preview, but in this talk I’ll show you how to start using it today, and what you’ll be able to do with it tomorrow.