Source : Free On-Line Dictionary of Computing

Tk
     
         A {GUI} library, generally used with
        {TCL} by {John Ousterhout}, but also available from within {C}
        or {Perl}.  Tk is available for {X Window System}, {Microsoft
        Windows} and {Macintosh}.  Tk looks very similar to {Motif}.
     
        Version 3.5.
     
        {(ftp://ftp.cs.berkeley.edu/ucb/tcl/)}.
     
        (1995-11-09)

tk
     
         The {country code} for Tokelau.
     
        (1999-01-27)