  Two families of exact simple solutions of Einstein field equations for
inhomogeneous stiff cosmologies are presented. The method to obtain the
solutions is based on the introduction of auxiliary functions in order to cast
the Einstein equations in such a way that can be explicitly integrated. Now,
despite of the equations are mathematically equivalent to the equations
obtained when the source of matter is a scalar field, is worth to mention that
the source that we consider is not a scalar field but a perfect fluid with the
stiff equation of state. The obtained solutions are expressed in terms of
simple functions of the used coordinates and two families of particular
solutions are considered. The geometrical and kinematical properties of the
solutions are then analyzed and the parameters are restricted in order to have
a physically acceptable behavior. The two particular solutions are of the
Petrov type I, the first one being regular everywhere whereas the second one
presents a big-bang singularity. Now, for a particular value of one of the
parameters, the second particular solution is a vacuum solution of the Bianchi
I type that reduces to the Kasner solution.
