Sure enough, TraceMonkey is present and accounted for in the Firefox 3.1 beta -- but it's not yet enabled by default.
Temporarily disabling major new features is a common way to break the software QA process into manageable chunks. So is adding the ability to re-enable these features, if you know where to find the "on" switch.
In this case, it's easy. Here's how to schedule your own personal play date with TraceMonkey in Firefox 3.1:
- First, of course, download and install the Firefox 3.1 beta. (Before you do, however, skip down to my caveats about installing and using a Firefox beta release)
- Launch the beta and type about:config in the URL bar.
- Double-click the true/false preference value and change it to true.
- Restart Firefox
Now, the caveat I promised: Installing Firefox 3.1 will overwrite an existing version of Firefox 3.0. The beta is already pretty solid, but it is bound to have some bugs at this point; in addition, many of your favorite Firefox extensions may or may not work with the beta release. (If you know what you're doing, of course, you can override extension compatibility checks, again at your own risk.)
Also, you should either know how to back up your Firefox profile or be prepared to lose it if something goes wrong.
Taken one at a time, Web-page performance issues don't seem very important. Add up the time, however, spent waiting for scores, or hundreds, or even thousands of pages to load, and you're talking about a significant productivity issue. That's why TraceMonkey is great news -- for Firefox users and also for Internet Explorer users who will benefit from Mozilla's efforts to set the browser performance bar higher than ever.