MUMPS
This is a language that pops up from time to time in stories online and has the added honor of being in actual production use storing critical life-safety information (i.e. patient records). However, this is also a language where terseness is appreciated and functions such as the following might appear in production code (example from the Wikipedia article on the topic):
s A="String" F i=1:1:$L(A) W $c($S($A($E(A,i))<91:$A($E(A,i))-52#26+65,1:$A($E(A,i))-84#26+97))