Some time ago I managed to get the DHTML Chess Widget working on this WordPress site. Below you can find Winning Chess Sacrifices and Combinations as a kind of exercise. You can make the moves by dragging and dropping a piece.
As soon as you have solved a problem the next problem will be loaded.
The widget works in Internet Explorer, Firefox and Chrome and the latest versions of Opera, but unfortunately not in Safari.
ChessTeacherLessons is also an interesting site to learn and improve your chess. At the moment there are more than 100 chess lessons on almost all the stages of the game and for all levels of play on this site. I advice to start at the chess lessons index page, but you can also navigate through the site by using the tags or categories.
The site doesn’t contain chess news and isn’t very frequently updated, but I like the chess lessons.
Update february 2015
ChessTeacherlessons has been discontinued, but the chess lessons are currently being moved to freechesslessons.blogspot.com
I have updated the link above.
Tim Krabbé’s Chess Curiosities looks like a very simple site and does not even have it’s own domain name, but the content of this site is really interesting. As the name indicates it contains a lot of chess curiosities. The most interesting parts are the Open chess diary and the chess records. The chess records are records from real games.
Chessville offers a lot of free high quality chess content, though not as much as ChessCafe and the front page is a little bit confusing. However it is certainly worth visiting this site and the list of columnists is very impressive.
The section that I have to recommend most is Tactics, so don’t forget to explore this area when visiting this site.