Konstantin Haase

It does exactly what it claims to do. It is a very fast, easy introduction to getting started with the Sinatra web framework for Ruby, a lightweight framework that avoids surprises apart from how surprisingly easy it is to get started. The book also covers a number of approaches to developing Sinatra web applications that are not well covered in online tutorials I have found. For someone who knows enough Ruby to get by, who wants to learn Sinatra, this book is a great introduction.