Those game annotations in Chess blogs - what are they?

I see a lot of Chess blogs that allow you to enter and play back games.  People annotate their games and let you step through them one move at a time.  They look great and they seem pretty similar, which makes me believe that there is a fairly standard, easy to integrate, inexpensive Chessboard control that people can incorporate into their blogs or web pages.

Does anyone have any recommendations?

As far as this site goes, when you come to post a new thread or comment, on the top left of the box you are typing in there is a little chessboard. When you hover your mouse over it, it says 'Insert position or game.' You can use that to insert positions or games into posts.

on each chess.com diagram there is an "embed" link where you can get the code to insert the game

The idea being that you first create and post the game here as N9NE suggested, perhaps in your chess.com blog, and then use the "embed" link to capture the game for use on pages outside of chess.com?