For those who have not come across Tcl (it is pronounced tickle) it is a tool command language, which is a scripting language for graphical windowing systems - typically those built upon X Windows, such as Motif. Visual Tcl is a toolkit - note it is NOT Tk - that provides a graphical widget based environment to Tcl. This is achieved with calls to the Motif window system, thus being really only of interest to those who work in this realm.
There is a lot to this book, but the well laid out reference sections for the library calls help to ease this. Perhaps the best part of learning a language like this, is the instant feedback you get. Early on you get to create widgets and dialogues, the result of which you can see in a pretty box on screen, which can be resized, scrolled, etc. More fun that purely some text saying hello world!
Once sufficient basics of Tcl are covered, the Visual toolkit (Vt) is then dealt with. The additions do not actually take up that much of the overall book, only about 100 pages. Since most of this section explains what the new Vt features are and how to use them, it does mean space is not wasted with it. The remaining 50% of the book is taken up with the command pages. It is this part of the book that is most likely to be used again. The commands listed are those for both textual Tcl, TclX and Vt. Thus for those just requiring Vt, a separate Tcl book is not required. Each command is clearly laid out with syntax, description and an example where appropriate.
Only of interest to those who have Motif as their windowing system with UNIX. Those wanting to learn Tcl and the more usually found Tk toolkit should look elsewhere. However, if you do have Motif and UNIX as you development environment, this book could help to make the creation of those odd little utilities we all have much easier and more fun.