  Einstein's spherically symmetric interior gravitational equations are
investigated. Following Synge's procedure, the most general solution of the
equations is furnished in case $T^{1}_{1}$ and $T^{4}_{4}$ are prescribed. The
existence of a total mass function, $M(r,t)$, is rigorously proved. Under
suitable restrictions on the total mass function, the Schwarzschild mass
$M(r,t)=m$, implicitly defines the boundary of the spherical body as $r=B(t)$.
Both Synge's junction conditions as well as the continuity of the second
fundamental form are examined and solved in a general manner. The weak energy
conditions for an \emph{arbitrary boost} are also considered. The most general
solution of the spherically symmetric anisotropic fluid model satisfying both
junction conditions is furnished. In the final section, various exotic
solutions are explored using the developed scheme including gravitational
instantons, interior $T$-domains and $D$-dimensional generalizations.
