Many products for a given objective always enrages fierce competition and comparison which results consumers bewildered.
Post browser war, one compelling reason that mandates me to use firefox browser is, presence of standard addons which sets itself distinguished from others. eg - firebug where the same variants in other browser is yet to yield the kind one experiences in firefox.
Earlier where I was insane in promoting Ubuntu and Firefox to every mammal in this terrestrial, they lack fundamentals like driver problems with ubuntu linux and firefox plugin update. The only alternative is to go for mac and safari/chrome browser.
Meanwhile, for the users who still pertain to firefox, there was an social bookmarking addon 'Delicious' and it is no more available in firefox addon repository. Intially Yahoo bought delicious to wet their users with social products and could not make butter out of water. Later AVOS ghastly bought delicious bookmarks and tortures its users with their rough skins. Only savior is to use firefox addon, to get rid of horrible skins. Now even that has been chopped.
For internet addicts, who install firefox fresh and crave for delicious addon in firefox repository, I believe post google search would land you here.
Download zip file and rename the extension to xpi. Hopefully this should work!! Enjoy!