LiveHTTPHeaders in Firefox 3.5

One of my favorite Mozilla Firefox add-ons has always been LiveHTTPHeaders: you can observe the HTTP headers being sent to and received from the server when a web page is requested. You can even have it record a bunch of requests as you click through a site to see the entire series of transactions.

One of the problems I’ve always had with LiveHTTPHeaders is that the project owners take their sweet time when it comes to new releases. For example, Firefox is currently on its 4th beta release of version 3.5 and yet LiveHTTPHeaders only works on versions 3.0.x.

I keep checking the project site for that magical “works with 3.5 beta”, but it never comes. The top comment on the project page is currently

Does all I expected it to do—and does it wonderfully. Wish it was compatible with FF3.1.

Today, I decided to do something about it. I’ve never poked inside a .xpi (“zippy”) file (the file format for product Mozilla add-ons) so I did some reading on Wikipedia. Turns out it’s just a ZIP file. If you open the ZIP file, you can see a series of files including install.rdf. RDF is just XML, so I checked out the contents of that file. The install.rdf file contains a bunch of information about the package itself, including the list of supported versions of various products (including Firefox, Flock, and Seamonkey). The setting for Firefox was


On a whim, I simply changed that to


and installed the .xpi into Firefox.

A quick ff restart later and it’s now working, apparently without any problems. Woo hoo!

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