Download Gamut
http://www.volity.org/projects/gamut/
There are four options there: a Mac OS X disk image, a full JAR file, and two Windows packages, one of which includes its copy of the Java runtime environment.
You can also visit the SVN at the time that the nightly build script ran.
(There is also a Java Web Start version, but it is currently disabled, due to ongoing bugs.)
Run Gamut
On a Mac or Windows system, double-click the icon. If you like Unix command lines, type:
java -jar Gamut.jar
You are now facing a dialog box that asks you to log into Jabber.
If you already have a Jabber account, you can use it. Type your Jabber address, and password.
(Note: Google Talk is based on Jabber technology, so you can use Gamut with a GTalk ID. Give name@gmail.com as your address.)
(All screenshots are from the Mac version. Win/Linux versions will have the menus attached to the window, instead of the top of the screen. If you have used Gamut before, the small help text will not appear. And, yes, all the screenshots say "Javolin" instead of "Gamut" -- that was an older name for the client.)
If you have no idea what a Jabber account is, check the "Register a new Jabber account" box.
Register a New Account
Fill out the registration form. Choose any username you like; put username@volity.net in the "Volity ID" field. Invent a password to use.
(You can also simply enter a username in the "Volity ID" field. The @volity.net part will be filled in for you.)
Note that the "full name" and "email address" fields may be required, or they may not. It depends on the Jabber server you are planning to use. (Volity.net allows you to leave these fields blank.)
You are now facing the main Gamut window, which displays your Jabber roster (buddy list).
Start a Game
The easiest way to start a game is from the Game Finder window. If no Game Finder window is open, you can open it by selecting "Game Finder" in the Window menu.
Note that the Game Finder that you see may not look exactly like this; its content is dynamically generated, and we are presently experimenting with its fetaures and layout.
Select a game -- in this example, "table.html" class=wikipagelink>table at a [Barsoomite Go] (also called "Branches and Twigs and Thorns").
You can also start a game by entering a parlor address directly. From the Game menu, select "New Table At..."
Type zarf-barsoom@volity.net. This is the ID of the Barsoomite Go parlor. You can also choose your nickname for the game. (This is essentially your "screen name" within the table chat system.)
After a brief pause, the game table will appear.
(Window is small to save bandwidth. If you increase the window size, the game board will scale smoothly to fit. Vector graphics are cool!)
Get Another Player to Join
The easiest way to get another player into the game is to send him an invitation through Gamut. First, your friend must be running Gamut and be logged in.
Second, your friend must be on your buddy roster. Press the "Add" button in the Roster window:
Type your friend's Jabber address. Then wait for him to acknowledge the action. Once he permits it, his name will appear in your Roster.
Then, hit the "Invite" button in the game window.
Enter your friend's Jabber address. (Or, you can drag his name from the Roster window to the "Invite" button, in which case his address will already be filled in.) You can also enter a chat message which will appear with the invitation. Send the invitation. The other player will see an invitation window appear, offering the option to join your game.
It is also possible to join a game without being invited. If you go to the Game Finder window, and select a game, you will see a list of open tables of that game. Click a table's link to join the table.
A third way is to type the table's address directly. This is somewhat unpleasant.
To do this, a player would have to run Gamut, and select "Join Table At..." (from the Game menu.) He would then have to type in the table ID.
The table ID is a string of the form ugly_letters_and_numbers@conference.volity.net. To determine this, you should select "Game Info..." in the Game menu:
The table ID is visible as the first line in the Game Info window. Email this to your friend.
Once he joins, his name will be visible in the player panel on the right.
Play Against Yourself
Gamut now supports playing a game against yourself. However, you have to be running two copies of the Gamut app. (On Mac, the easiest way to do this is to double-click on the jar file inside the app bundle.) You'll need to log in separately in each one. Use the same Jabber address and password.
Start a new table in one Gamut, and then join (using "Join Table At..." or the Game Finder) in the other one. Be sure to use different table nicknames in the two apps -- the system won't let you join the table twice with the same nickname.
Start Playing
To begin the game, you must each sit down (the "Seat" button) and then declare yourself ready (the "Ready" button).
Note that you must both sit down before you push "Ready". The "Ready" button indicates that you are satisfied with the current seating arrangement. If only one player is seated, it's not a viable game, so "Ready" won't work.
Then you can play. White moves first. Drag and drop pieces from your stash to the board; hit "Go" when you're satisfied with your move. (Orientation is automatic. In BT&T, once you've selected a square, there's always a best direction to point -- or a choice between directions where it doesn't matter which you choose. So the computer can orient you correctly.)
The game is over when both players have made all their moves.