The program interface and operation are currently again quality. The quality of the Engine is in my opinion absolutely in order, but not with a serious advantage in the duel mode outside of the tournament were even other stronger.
Open Source program Stockfish which is under the GNU General Public License, and of which a Stockfish itself is also a "World's Strongest Chess Engine" is called, run Komodo.
It is a fact: those who have a Engine searches, against which you play, you can learn and also up to date, may be accessed here.
You can free download Stockfish and safe install the latest trial or new full version for Windows 10 (x32, 64 bit) from the official site.