This may help your evaluation: http://en.wikipedia.org/wiki/Reduce_(higher-order_function)

Looks like most languages call it `fold`, or the more specific `foldl` and `foldr`. `reduce`, or some variant, is the 2nd most common, used in in Lisp (and variants like Clojure) and Perl, Python, Javascript, etc. The only other languages that use `inject` are Smalltalk and Groovy.