Nick Ing-Simmons was the auther of Perl/Tk. He died of a heart attack at the age of 48 on 2006-09-26.
RLH 2006-09-26: That is sad. Nick was always very helpful.
AMG: Not to take anything away from Nick, but the linked article and its comments attribute the development of Tk itself to Nick. Sample quote: "Tk was initially born out of frustration that perl didn't have a native GUI at the time. Nick tirelessly developed Tk for over a decade." Tcl isn't mentioned even once in the article or its comments.
I guess the charitable interpretation is that "Tk" is meant as the name of the Perl module which he did develop, not the like-named GUI toolkit with which it interfaces.