Experienced in Smalltalk once professionaly, now as hobbyist.
Fluent in C,C++,FORTRAN,matlab and knows a useful pile of dark sides of these languages.
Notions in Prolog,Ada,Pascal,Lisp (a pity I didn't knew Scheme),shells.
Never used assembler since 16bits era, but consider Assembler an essential step in learning IT.
Interested in Haskell, but don't have courage to extend curiosity to Clojure & co.
After Smalltalk, can't use Java, Perl, Ruby, but could have to use Python, and still consider having a lot to learn from other languages.
Did some unix admin of small business unit, and used some LaTeX long ago.
IT are just tools, not goals in my business.
Not afraid by maths.