  We exhibit a simple and explicit formula for the metric of an arbitrary
static spherically symmetric perfect fluid spacetime. This class of metrics
depends on one freely specifiable monotone non-increasing generating function.
We also investigate various regularity conditions, and the constraints they
impose. Because we never make any assumptions as to the nature (or even the
existence) of an equation of state, this technique is useful in situations
where the equation of state is for whatever reason uncertain or unknown.
  To illustrate the power of the method we exhibit a new form of the
``Goldman--I'' exact solution and calculate its total mass. This is a
three-parameter closed-form exact solution given in terms of algebraic
combinations of quadratics. It interpolates between (and thereby unifies) at
least six other reasonably well-known exact solutions.
