ZZT-OOP! Oh, the nostalgia. That was awesome. Well, not the language. Not the IDE. But the whole idea of a game having a built-in programming language. Was it the first of its kind? (Then again, in 1991, I don't suppose it was.)
JFYI, FORTH is now usually written Forth. (Like LISP is now normally written Lisp.)
Off the top of my head:
Ada, BCPL, C, Delphi, Erlang, Fortran, Godel, Haskell, Intercal, Java, K (if hypothetical languages count? This is a project by some FreeBSD developers to produce a more powerful version of C designed for kernel programming), Logo, Maple, N??, Occam, Pascal, Q??, Ratfor, Sed, TeX, U??, Visual Basic (if this counts as a language in itself rather than as a version of BASIC), Whitespace, X??, Yorick, Z??
I guess that's 19-21 out of 26, depending on the exact rules.
Paul Graham has most of the work done for me: http://paulgraham.com/lisps.html
He has A, B, C, D, E, F, G, I, J, K, L, M, N, O, P, S, V, and X - though I certainly can name some dialects of the same letters which are not listed. Not going to really bother on that one, though.