Backgammon Server is a place to play Free Online Backgammon Game. There are a lot of them now and here is a list of all the ones I know about. There are a few not listed but they aren't up and fully functional yet.
If you are interested in placing wagers on your backgammon skills check out this site for backgammon for money.
I have personally tried out most of them at one time or another but there are a few here that I haven't. Many of them are general games servers and have very little backgammon action.
I would suggest trying out as many backgammon softwares as you can and giving them all a chance as they all have different things to offer and any of them could be the "right" one for you.
If you are looking for guidance however, here is a top six list of places I have played that seem to be the most populated and will probably be around for awhile.
These servers only offer backgammon. But it requires you to download special client software to play.FIBS
First Internet Backgammon Server, the original. All platforms, can also play by telnet, without special software. Free.
These are seful links to online backgammon:
These servers offer other games too. They require you to download special client software to play.
These servers also offer other games. You play via your web browser, usually with Java, so they don't require any additional software.
Some of these servers also offer other games. You play via your web browser, usually with Java, so they don't require any additional software. Or you can play by email and look at a picture of the board.