Well, it appear there's an alpha version available which do support Firefox at
http://tech.groups.yahoo.com/group/delicious-firefox-extension/files/
(you will need a Yahoo login)
snips below from the announcement at delicious-firefox-extension group on yahoo
I'm pleased to announce that we've just uploaded a new version of the extension to the group. It has a variety of changes, which I'll describe below.
Status bar indicators for new links for you and network activity
FF3 support (like you'd think we'd forget)
Anyway, unlike previous beta releases, we are calling this release an
`alpha' release. Much like the Firefox beta releases, this release is
meant to provide you with a preview of upcoming features. Some of
the features and interface choices are experimental and may change a
lot before we launch, but we're eager to hear your feedback on the
changes, especially if you think we can do certain things better.
Just like with any of the previous prerelease extensions, the
following caveats apply.
The del.icio.us team has been using this extension daily with no
serious ill effects, but anything can happen, including the loss of
bookmarks and data. We will do everything we can to help you if our
extension somehow chews up your bookmarks, but we can't guarantee success
The registration wizard is disabled for the alpha release. If you
install this extension and are somehow not already a del.icio.us user,
register via the typical web route and you can use the extension.
This extension has been tested and updated to work with FF3 Beta 5.
As each FF3 beta has changed enough for us to make changes to our
extension, subsequent FF3 releases may have issues. Please report
these, and we will do our best to get updates out ASAP.
