  For autonomous delay differential equations $x'(t)=f(x_t)$ we construct a
continuous semiflow of continuously differentiable solution operators
$x_0\mapsto x_t$, $t\ge0$, on open subsets of the Fr\'echet space
$C((-\infty,0],\mathbb{R}^n)$. For nonautonomous equations this yields a
continuous process of differentiable solution operators. As an application we
obtain processes which incorporate all solutions of Volterra
integro-differential equations $x'(t)=\int_0^tk(t,s)h(x(s))ds$
