Google has done a fantastic job with abstracting the need to know the browser specific code when using GWT for the browsers it supports. What if you are using the GWT and you come across a browser that isn't supported? Are you able to modify the code generated by the toolkit?
As much as possible the widgets in the toolkit use the DOM class, a helper class which is used to interface with the HTML DOM. Packaged in GWT there are several versions of the DOM class, each specific to a browser(s). So, if you are lucky, you will only need to create your own DOM implementation, specific to your browser, alter some config files, and everything will work just fine.
On the other hand, things aren't always that easy, so it hard to say without the specifics of the browser you wanted to target.
Netscape 4.x has the power and speed that anyone can dream about using! It is cutting edge with document.layers! I think we should ask for GWT to figure out a way to support it. If you believe me still, how about we get GWT to support Lynx.
Good Luck with the book!!
Eric [ June 26, 2007: Message edited by: Eric Pascarello ]