Presidents are in principle programs.
Gorbachev is a raw prototype, possibly an alpha version. It seems to be the president, but it is better not to put it, or it can crash the system.
Yeltsin is already a beta. Thus e. and bugs are full, and it does nothing useful, but it can already be carefully shown to others. The system may not collapse, but working with it is a pleasure below the default.
Putin is like a relief. The first thing is not to be ashamed of others. And bugs are not visible, or carefully quickly concealed by media patches.
Medvedev is now President 2.0. The whole social. Internet support, hypertext vector feed and cellular communications networks have been added.