Changes to Tcl between r5 and r6

'''Tool Command Language'''

Tcl is a dynamic programming language that is available on many platforms. --> Tcl is a dynamic programming language that is available on many platforms.  Tcl is very flexible and consistent.  For example, you can re-implement the "if" command within Tcl (see [Reimplementing the If Statement in Tcl])

Some links:
   * http://www.tcl.tk/
   * http://wiki.tcl.tk/
----
'''Tcl Documentation'''
   * Tcl Cheat Sheet [http://home.houston.rr.com/brianohagan/tcl_tk_ref_guide.html] (PDF [http://www.rkeene.org/projects/info/resources/tcl/docs/tcl-tk-reference-guide.pdf])
   * [Tcl and Threads]

Legend

     Only in r5
     Only in r6
     -->      Modified slightly between r5 and r6