You can find the full source code for this website in the Seam package in the directory /examples/wiki. It is licensed under the LGPL.
For reasons I cannot explain, sites powered by the Seam wiki (e.g., seamframework.org and in.relation.to) do not render out of the box in Opera (9.6 on Linux, at least). When you request the URL, you get a blank screen and possibly a perpetual spinner.
Fortunately, there is a pretty simple workaround. You just spoof the user agent string so that Opera masks itself as Firefox. There are two levels of masking. The first uses the built-in Browser Identification setting in Opera. To activate it, follow these steps:
* The User Agent Spoof Script was adopted from http://www.scss.com.au/family/andrew/opera/browserids