"The main guide to Tcl is Tcl and the Tk Toolkit by John Ousterhout (Reading, MA: Addison-Wesley, 1994), the creator of Tcl."
– Unix Review
"The definitive source of information on the system is John Ousterhout's book, Tcl and the Tk Toolkit, published by Addison-Wesley."
– Linux Journal
"Overall, Ousterhout has provided an excellent overview (Tcl and the Tk Toolkit)of a very useful piece of software. If you're thinking of building or customizing a graphical user interface, you won't find many guides better than this."
– IEEE Computer
"This is an extremely well-written book, containing many figures, tables, examples, and scripts to illustrate the Tcl and Tk concepts. His presentation technique and expertise result in a superb text. I enjoyed Tcl and the Tk Toolkit and recommend it highly to anyone with any shell writing experience. Everyone who uses the X Window System will find this book helpful."
– Sys Admin