In the drafts of books created so far, there are links inside the books between the views. The links are placed inside the book, at the end of each section. There are also links between the views in the about pages, e.g. on the about page showing the URLs used in a book. In the web versions of the books, there are also links in the sidebar of each page.
Recently I added links between the views directly after figures showing code. As an example of this later feature, you can take a look at Figure 1 in Into Programming, where you can see the links to the other views.
The links works as illustrated in this figure (click the figure to get a larger version), where some text and some code from a program, written in C in one view and written in Java in another view, is shown.
As you can see in the above figure, parts of the text are common for both programs, and other parts of the text are different. The code of course is different, since that is the whole point of having these views, with one view for each programming language!
The connections between the views are shown in the figure as dashed red arrows, corresponding to the hyperlinks you will find inside the book.