Similar (but opposite ?!) to Reverse Polish Notation, in that operators act on the next two expressions (for binary operators).
Eg 5 + (6 * 7) is expressed in prefix notation as
However, as RPN uses a "stack" of intermediate values it is easier to implement as when you parse an operator you already have your operands available.
LISP is probably the best known language to use prefix notation.
One page links to PrefixNotation:
