To use:

Run chalkbox with an 'a' (Anarchy) or a 'p' (Polite) on the command
line.  To add a user, click on "add user" and then type the name of the
new user into the popup.

In anarchy mode, clicking on one of the people in the chalkbox gives
that person the chalk.  You can click on yourself to take the chalk.

In polite mode, clicking on a person will give that person the chalk
only if you already have it.  If you do not have the chalk, you can
click on yourself to raise your hand, and hope that the person with
the chalk will click on you.

To connect the chalkbox to an application, click on the "choose
app" button, and after the cursor changes to a crosshair, click on
an application.

Problems:

When connecting the chalkbox to an application, you must click on the
original window, and not one of the replicated ones.  This is because
the XMUX_STATUS atom isn't properly copied to the replicated windows,
and it gets out of sysc with the XMUX_HOSTS atom.