there were two big updates in both nodejs and express. current node versions are now 4.x and 5.x and express is now 4.x (instead 3.x, used in the book). if you follow the code examples and you do for instance 'npm install express' you'll get latest express (4.x) and some of the examples didn't work for me as breaking changes in express 4.x were introduced.
so be aware of that before you buy the book. either you fix the code by yourself or you wait for a second edition of this book.
but nevertheless it's a great book and helped me to get started with node and express.
... completely, what's the reason for the omega plus first web server language / framework system.
But let's start from the begin:
as is often the case for books covering the latest IT hype technology, it's tricky to stay abreast new developments. This book, however, differs and manages to distill the essentials out of the useless.
node.js is a new environment and it's not that well documented yet for all its APIs and how things are mixed together from jQuery over npm and nodeclipse, css, html, and I've probably forgotten another bunch of more or less arcane technologies.
One wonders how brittle the IT environments of the future shall be and who will be able to maintain the latest fads; fads being created at today's internet speed. it used to be called software engineering, but has evolved into software banging.