ideachess, one of the top 3 free chess tactis training sites in the world, has now a whole new chessboard that has allowed us to overcome the limitations of the previous one.
Now you can enjoy, compare yourself with others and improve your tactical preparation on Windows, Linux, Mac, and even with your tablet without the need to install any software and safely.

http://www.ideachess.com

Players from 198 countries in the world train himself regularly on ideachess.