FreeSoftwareBooks.com
the name says it all

Home Page  |   Languages   | Java/J2EE    |  Microsoft    |   Unix/Linux    |   Computer Science    |   Databases    |  Web   |   Networking  
Tcl/Tk Scripting 
TCLWISE: An introduction to the Tcl programming language (S. Sanfilippo)
Practical Programming in Tcl and Tk Tcl/Tk for Programmers
Tcl/Tk Cookbook (L. Sastry, et al) [Mirror] Introduction to TCL/TK
An Introduction to Tkinter Annotated Network Diagram Visualisation using Tcl/Tk
The Linux Tcl and Tk HOWTO (L. Rossetti) Mastering Perl/Tk (S. Lidie, N. Walsh)