The scalar math module is complete and ready to be tested. It should speed up code that relies heavily on scalar arithmetic by by-passing the ufunc machinery. It needs lots of testing to be sure that it is doing the "right" thing. To enable scalarmath you need to import numpy.core.scalarmath You cannot disable it once it's enabled except by restarting Python. If we need that feature we can add it. The array scalars respond to the error modes of ufuncs. There is an experimental function called alter_scalars that replaces the Python int, float, and complex number tables with the array scalar equivalents. Thus, to amaze (or seriously annoy) your Python friends you can do import numpy.core.scalarmath as ncs ncs.alter_scalars(int) 1 / 0 This will return 0 unless you change the error modes... ncs.retore_scalars(int) Will put things back the way Guido intended.... Please try it out and send us error reports. Many thanks to Sasha for his help in getting all the code so it at least compiles and loads. All bugs should be blamed on me, though... Best, -Travis