This article is from 2004. Technologies and best practices have evolved since then.
I recognized that the extension I missed so much after installing the latest version of Mozilla Firefox is now ready for 1.0PR. Now you can do all the things a developer needs to do. The LiveHTTPHeaders extension helps you by:
- adding a "Headers" tab in "View Page Info" of a web page
- adding a tool in the "Tools" menu to be able to display http headers in real time (while pages are being downloaded from the Internet)
- letting you edit request headers and replay an URL (I have to say I didn't find out where this feature is located)
Now you don't have to guess anymore if gzip is really working or not. Just have a look at the headers! Additionally you can debug a web application easily, see which kind of web server the remote site is using and the cookies sent by remote site.