How do I get seamframework.org to work in Opera?

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:

1. Enter http://seamframework.org in the location bar of Opera and press Enter
2. Select Tools > Quick Preferences > Edit Site Preferences... in the Opera menu bar
3. Switch to the Network tab
4. Change the value of the Browser Identification field to Mask as Firefox
5. Click the OK button
6. Press the Stop button followed by the Refresh button in the Opera address bar

That setting may or may not work. For me, it works for seamframework.org but not in.relation.to. Likely the Browser Identification is not sufficient because the rendering problem lies somewhere in JavaScript evaluation. Thus, you need to go deeper and get Opera not only to mask as Firefox, but to behave as Firefox. To accomplish that, you need to apply a user script which manipulates the implicit JavaScript objects. To activate this script, follow these steps.

1. Enter http://seamframework.org in the location bar of Opera and press Enter
2. Select Tools > Quick Preferences > Edit Site Preferences... in the Opera menu bar
3. Switch to the Scripting tab
4. Download the attachment Opera User Agent Spoof Script[1] *
5. Click the Browse... button next to the User JavaScript files field and select the opera-uaspoof.js file you downloaded
6. Click the OK button
7. Press the Stop button followed by the Refresh button in the Opera address bar

* The User Agent Spoof Script was adopted from http://www.scss.com.au/family/andrew/opera/browserids