The Tcl/Tk combination is increasingly popular because it lets you produce sophisticated graphical interfaces with a few easy commands, develop and change scripts quickly, and conveniently tie together existing utilities or programming libraries. The
Tcl/Tk Pocket Reference
,a handy reference guide to the basic Tcl language elements, Tcl and Tk commands, and Tk widgets, is a companion volume to
Tcl/Tk in a Nutshell
.