Rated 4 out of 5 stars
A very convenient tool and promises to be a standard item in a web developer's toolbox.
An improvement over "HTTP Resource Test" in the following regards: 1) Context-aware so you can easily find response of already opened tabs. 2) Possesses more (all?) HTTP methods. 3) Syntax highlighting is nice. 4) By being a full-blown window, one can use "find" on the results. 5) Header response names are bolded. 6) Has back button and back/forward keyboard capability. 7) Gives response time. 8) Has flexibility in typing raw text for headers. 9) Convenient in being able to directly insert a header and value.
Advantages of "HTTP Resource Test" over this add-on:1) Has a way to send a message body (for POST or even GET). 2) Textarea response is convenient for copying. 3) Window is resizable. 4) More elegant in appearance as far as header request building.
General Complaints/Suggestions: 1) Syntax highlighter currently doesn't allow grabbing of source text (gives an error). 2) It would be better to retrieve current tab responses from the cache (nsICacheService) than making a new request when first opening view response. 3) It was not immediately obvious to me what the textareas are for (even though the first one becomes clear with using the pull-down), and I still am not clear on what the second one does--apparently it works with URL encoding/decoding? Anything else?. 4) A (contextual) visible forward button would be useful. 5) An option to edit the sample header/values menu contents would be awesome.