<p>I am looking for either a FireFox extension, or a similar program, that allows you to craft GET and POST requests. The user would put in a form action, and as many form key/value pairs as desired. It would also send any cookie information (or send the current cookies from any domain the user chooses.) The Web Developer add-on is almost what I'm looking for; It let's you quickly see the form keys, but it doesn't let you change them or add new ones (which leads to a lot of painful JavaScript in the address bar...)</p>

[{'answer_id': 15751, 'author': 'David Schlosnagle', 'author_id': 1750, 'author_profile': 'https://Stackoverflow.com/users/1750', 'pm_score': 2, 'selected': False, 'text': '<p>You may want to check out the <a href="https://addons.mozilla.org/en-US/firefox/addon/966" rel="nofollow noreferrer">Tamper Data</a> extension which allows you to easily intercept and manipulate the request parameters among other features.</p>\n'}, {'answer_id': 16030, 'author': 'Ian Oxley', 'author_id': 1904, 'author_profile': 'https://Stackoverflow.com/users/1904', 'pm_score': 0, 'selected': False, 'text': '<p>If you\'ve got Greasemonkey installed you might want to try the XSS Assistant user script: <a href="http://www.whiteacid.org/greasemonkey/#xss_assistant" rel="nofollow noreferrer">http://www.whiteacid.org/greasemonkey/#xss_assistant</a></p>\n'}, {'answer_id': 16035, 'author': 'Cebjyre', 'author_id': 1612, 'author_profile': 'https://Stackoverflow.com/users/1612', 'pm_score': 0, 'selected': False, 'text': '<p>The <a href="https://addons.mozilla.org/en-US/firefox/addon/6622" rel="nofollow noreferrer">DOM Inspector</a> will let you add/edit/remove inputs - copying existing ones is the easiest way of adding new ones. I highly recommend getting <a href="https://addons.mozilla.org/en-US/firefox/addon/1913" rel="nofollow noreferrer">Inspect This</a> as well.</p>\n'}, {'answer_id': 16056, 'author': 'Dale Ragan', 'author_id': 1117, 'author_profile': 'https://Stackoverflow.com/users/1117', 'pm_score': 3, 'selected': False, 'text': '<p>If you\'re a windows user, use <a href="http://www.fiddler2.com/fiddler2/version.asp" rel="nofollow noreferrer">Fiddler</a>.  It is invaluable for looking at the raw Http requests and responses.  It also has the ability to create requests with the request builder and it has an auto responder also, so you can intercept requests.  It even lets you inspect HTTPS traffic and it has a built in event scripting engine, where you can create your own rules.</p>\n'}, {'answer_id': 26865, 'author': 'dlamblin', 'author_id': 459, 'author_profile': 'https://Stackoverflow.com/users/459', 'pm_score': 3, 'selected': True, 'text': '<p>Actually I think <a href="https://addons.mozilla.org/en-US/firefox/addon/2691" rel="nofollow noreferrer">Poster</a> is what you\'re looking for.</p>\n\n<p><a href="https://addons.mozilla.org/img/uploads/previews/full/19/19951.png" rel="nofollow noreferrer">A Screen shot of an older Poster version</a></p>\n'}, {'answer_id': 41017, 'author': 'chs', 'author_id': 4325, 'author_profile': 'https://Stackoverflow.com/users/4325', 'pm_score': 0, 'selected': False, 'text': '<p>Look for a extension called Poster.</p>\n'}, {'answer_id': 442676, 'author': 'PhiLho', 'author_id': 15459, 'author_profile': 'https://Stackoverflow.com/users/15459', 'pm_score': 0, 'selected': False, 'text': '<p>Poster looks nice and complete. For reference, I will add <a href="http://urlparams.blogwart.com/share/index.php" rel="nofollow noreferrer" title="UrlParams">UrlParams</a> to the list, but looks like Poster is better.</p>\n'}, {'answer_id': 5002302, 'author': 'user616639', 'author_id': 616639, 'author_profile': 'https://Stackoverflow.com/users/616639', 'pm_score': 0, 'selected': False, 'text': '<p>I think tamper data would do the trick....live http headers addon would also do the same.</p>\n'}]
['https://Stackoverflow.com/questions/15731', 'https://Stackoverflow.com', 'https://Stackoverflow.com/users/26/']