There's some cutting edge stuff covered in this book.
Some of it is still in the specification stages and hasn't yet made it into the latest browsers.
There's some great examples of CSS3 stuff going on with things like text displayed on an 45 degree angle, and rounded corners.
The information on sockets is pretty cool. If you've done stuff with Adobe Flex, and things like long-polling/streaming you'll appreciate how full duplex communication is going to reduce network traffic by getting rid of the overhead of bulky HTTP headers.
I think the geolocation stuff is a bit hit and miss. Atmospherics sometimes make it difficult for browsers to pinpoint you based on Wi-fi triangulation the Google guys captured. The response can take forever (or timeout) under these conditions.
Chapter 9 I couldn't get to work in any browser. (Safari 5.02, Chrome 7, Opera 10.63, or Firefox 4.0.6b)
Although this is no fault of the book. It also highlights what an mess browser vendors are making of things. Although Safari 5 is supposed to support canvas and video, there is a chapter where a video plays and at 5 second intervals a 4 by 4 grid gets filled up with a timeline snapshot. Every browser but Safari worked fine here).
Then you come to the geolocation API. Safari, sends back a timestamp, in seconds since Jan 1st 2001. So to compensate in Safari you need to do something like this
var delta = Date.parse(new Date(2001,0,1,0,0,0,0)); var tsmilli = (geots * 1000) + delta; var timestamp = new Date(tsmilli).toUTCString();
What a palaver! (The book doesn't show this level of detail. It was something I figured out for myself).
There was also a chapter on Form validation. The password validation routine didn't work in any browser (I think this is down to the fact that setCustomValidity is yet to be implemented in any of the aforementioned browsers). In the form validation area, Opera shines, but the rest of the browsers tend to suck. Things like ranges are handled well by all browsers bar Firefox. Datepickers are an abomination in Chrome & Safari.
Server-side the book uses some Python scripts.
I didn't think much of the use case they guys came up with for the Web Workers API either (and the authors aren't responsive to emails).
I'd recommend anyone to use Google's Chrome as a browser of choice. Overall it performs the best of all the browsers if you want to live life on the cutting edge.