I have a weakness for programming languages. Given the time and opportunity, I would gladly learn a new one every few months, and apart from TeX (in its programming language guise) and Perl, which I both abhor because of their atrocious syntax, I usually find something to like in all languages. I have even composed what may be the only illustrated children story ever written in pure Postscript (“The story of the triangle that grew”.) But my favorite language remains Lisp, especially in its Common Lisp variant, which is the one I know best (with Emacs Lisp a close second). I was therefore saddened to learn today of that the creator of Lisp, John McCarthy, recently passed away.
(Interestingly, according to Wikipedia, McCarthy had a PhD in math under Lefschetz…)