If modifying the document is the slowest part, you could try adding all the links to a temporary document fragment, then adding that to the document.

Good idea, Carey! Alas, while it might be marginally faster, it's definitely still way too slow. It appears that the implementation of appendChild() with a document fragment is to iterate over the nodes in the fragment, adding each one :-(

According to PPK's benchmarks, innerHTML is thrice as fast as the DOM in Mozilla. Maybe you could try that to add the links. (You may have heard it didn't work in XHTML pages, but that's been fixed in Firefox 1.5.)

As for asynchrony, there's always window.setTimeout() . Though it's unlikely an extension would notice links added to the page after it's done loading, unless the author specifically expected such a thing to happen.

(P.S. Along with the article itself, could you also show the previous comments as well in the comment editing page? Oh, and the cmSiteNavigation link and the images are broken here, though they're OK in the original article, and most other URLs are fine here as well... That's strange.)

Thanks, Rahul, I'll take a look when I can.

Regarding your P.S.: No. The way the essay that you're commenting on is displayed on the comments page is a complete hack. I don't think there's a practical way for me to improve it. Well, I'm sure it could be done, but not easily. It's a long way down on my list of things to do :-(

FYI: using innerHTML didn't help.