One of the new features in Firefox 2 is Microsummaries, which essentially allows dynamic bookmark titles. This is useful when bookmarking volatile pages, since the title can reflect the current state of the document rather than the state when the bookmark was created.
The system works by registering XSLT transformations that generate a simple text string from the page content. The registrations are either done via a <link> element, or matched via regular expressions. The system is designed to target users (who can register their own microsummary generators), website owners (who can suggest a generator through a <link> tag) and 3rd parties (who can provide generators for other sites to users).
For Launchpad, I’d fall into the second category. It would be nice to provide microsummary generators for bug pages, so you’d get an indication of the status of the bug, plus an up to date bug title. Now while all this information is available in the page content, we can provide it in a much more efficient manner (if we know the user is only interested in generating a microsummary, why send them the 100 comments on the bug every time the bookmark title is to be updated?).
Being able to specify a transformation for the bookmarked URL that would be used instead for generating the summary would be one way of solving this. This would reduce the bandwidth requirements and processing time on our end. Another way would be for Firefox to include something in its request that would allow a site to know that the page was being retrieved for microsummary generation so it could ommit information.
Overall it looks like a useful feature, but I do wonder if it will suffer from the “RSS effect” and cause lots of needless traffic to web sites until people work out how to achieve the same effects in a less resource intensive fashion.