A great, 250 page introduction into Mono, the open source implementation of a C# compiler and accompanying runtime environment (or the other way round).

After reading this book you can compare C# with other languages, like Java, and you’ll have worked through some applications in C# with the Gtk UI toolkit and Mono’s ASP.NET implementation.

The only question that remains is: Why isn’t there an Edie Freedman drawing on the cover of O’Reilly Developer Notebooks?