  A few examples of quickly developing field of double parton scattering are
discussed. We present arguments that the production of two pairs of charm
quark-antiquark is the golden reaction to study the double parton scattering
effects. We discuss briefly also mechanism of single parton scattering and show
that it gives much smaller contribution to the $c \bar c c \bar c$ final state.
In this context we discuss also the contribution of perturbative
parton-splitting mechanism which should also be added to the conventional DPS
mechanism. The presence of the letter leads to collision energy and other
kinematical variables dependence of so-called $\sigma_{eff}$. We briefly
discuss production of four jets. We concentrate on estimation of the
contribution of DPS for jets widely separated in rapidity. Finally we briefly
mention about DPS effects in production of $W^+ W^-$.
