Extensions.checkCompatibility.4.0 | ReeCreate Blog http://www.reecreate.com/blog/tag/extensions-checkcompatibility-4-0/
delicious support forum – Using delicious with Firefox 4.x http://support.delicious.com/forum/comments.php?DiscussionID=6201
Installing delicious bookmarks extension in Firefox 4 RC | James Moss http://jamesmoss.co.uk/blog/installing-delicious-bookmarks-extension-in-firefox-4-rc/