Does octave have a "native" format? Would it make sense to use hdf5?
That may be useful since it is supposed to be a sort of universal
format. Octave can read hdf5 right now. I'm not sure what all else,
but maybe with some more tools supporting it it could gain some
momentum. I haven't really looked at it, but hopefully it would not
have the following problem that matlab .mat file format has. In a .mat
file you have to write out all of each vector/matrix before starting on
the next one. This is a bummer if you're writing out time points from a
simulator.