Tk

1. Short for toolkit, Tk is a library of GUI elements that was first included with Tcl to help promote and allow for the development of a GUI interface. Today, many other languages such as Perl include their own Tk, which is in part or all of the Tcl/Tk libraries.
   
   Complete information about Tcl/Tk can be found at: http://www.tcl.tk/
    
2. .tk is also a domain suffix for Tokelau.

Also see: Perl, Programming definitions, Tcl