Changes 3.0.0:
* Compatibility with Matlab graphics is much better now.  We now
  have some graphics features that work like Matlab's Handle
  Graphics (tm):
* The way Octave handles search paths has changed.
* Previous versions of Octave had a number of built-in variables to
  control warnings (for example, warn_divide_by_zero).  These
  variables have been replaced by warning identifiers that are used
  with the warning function to control the state of warnings.
* All built-in variables have been converted to functions.
* For compatibility with Matlab, the output order of Octave's
  "system" function has changed.
* For compatibility with Matlab, the output of Octave's fsolve
  function has been changed.
* For compatibility with Matlab, normcdf, norminv, normpdf, and
  normrnd have been modified to compute distributions using the
  standard deviation instead of the variance.
* For compatibility with Matlab, gamcdf, gaminv, gampdf, gamrnd,
  expcdf, expinv, exppdf and exprnd have been modified to compute
  the distributions using the standard scale factor rather than
  one over the scale factor.

(adam)