The basic exit node functionality is implemented. However the client does not yet support the wallet API.
Prototype software, use at your own peril.
Copy the config/config.sample.js file to config/config.js and make any necessary adjustments.
This defines the default settings for all users of your installation.
Check out the code using
git clone git://github.com/bitcoinjs/bitcoinjs-gui.git --recursive
From there, just make sure bitcoinjs-gui/index.html is accessible through an HTTP server.
Open the URL for bitcoinjs-gui in your browser.