The Fast Light Tool Kit (FLTK) (http://www.fltk.org) binding for Tcl/Tk is a dynamic extension to the Tcl/Tk application development environment that implements a GUI development environment based on the FLTK library. This Tk look alike has a rich widget set that can be used for the rapid development of GUI appliactions. The extension is available for both RH Linux and MS Windows in the form of binary distribution, and is also available as a source distribution. The FLTK extension allows for the development of GUI applications using Tcl commands in a manner similar to the Tk extension, but is considerably more economical in terms of code size. FLTK appliactions use a native interface to their host platforms, and consequently are typically faster than equivalent Tk application.

Some technical notes based on other work that I have done:

   * [Performance of networking applications]
   * [Using MFC Controls as Tk Widgets]
   * [Tcl Socket Performance] Some test results on Tcl socket performance on different ethernet implementations.

Quite a few extensions that I have written for Tcl/Tk for my own use are available from my home page at:
http://pages.infinit.net/cclients/software.htm

'''What: Grab'''

Description: 

General purpose window capture functionality for use with Tcl scripts under Windows, provided as a console command version.
Currently at version 1.0.

'''What: Image'''

Description: 

Stubs based Windows extension for Tcl 8.2.0 and later, providing a range of image processing functions useful for  manipulating images in color index format. Reads image data from BMP, GIF, JPEG, PNG, TIFF formats and supports a RAW file format.

Does NOT use Tk and does no visualization. Currently at version 1.1. 

'''What: Variety of Windows extensions (Findleton)'''

Description: 

Currently available are extensions that support DDE (v 203),  Winhelp 2.0), printing (tkprint 1.1.6), frame animation, BMP creation, and an extension that does "everything" that DDEML does, including being able to write DDEML servers entirely in Tcl.

'''What: Containers'''
 
Description: 

Small Tcl extension that implements basic container objects, such  as bag, queue, tree, priority queue, random queue, struct, stack, hash, FIFO, LIFO, etc.  Code is in C++, using templates.

Free for non-commercial use, written permission of author otherwise.

Source available, as well as a binary distribution for Windows.

Currently at version 1.1.