  We consider quantization of open string theories in linear dilaton and
constant antisymmetric tensor backgrounds and discuss the noncommutativity of
space-time coordinates arising in such theories, including their relationship
with light-like noncommutativity as well as backgrounds with null isometries.
It is argued that the results can also be understood using space-time equations
of motion of the string modes. We then present N= 2 supersymmetric
generalization of these theories and the associated noncommutativity structure.
