WARNING: I don't actively use this myself any more. I wrote BetterQuest which I now use instead. If you're not incredibly wedded to FuBar, I'd recommend switching.
This is a quest-tracker replacement plugin for FuBar. It provides a tooltip which replicates /most/ of the information from the quest log. It can display (or not): quest level, difficulty, objectives, zones, and suchlike. It will put quest information into the tooltips for quest monsters and items. It will make quest levels appear when talking to NPCs.
If other people in your party are using QuestsFu it'll show you how many of each quest objective they've gathered.
If you want it to, and don't think it will annoy people, you can send a message to party chat when you advance a quest objective.
Shift-click on quests in the tooltip to copy the title to the chatbox if it's open. Control+Shift-click on quests in the tooltip to copy their objectives and status to the chatbox if it's open. Control-click on quests in the tooltip to share them with your party. Alt-click on quests in the tooltip to add them to Blizzard's quest-tracker.
QuestsFu includes a replacement for the Blizzard built-in quest tracker, which can track more than 10 quests at a time. Right-click on it to adjust its scale and coloration. (Or alt-right-click if you've locked the tracker.)
Achievements show up in QuestsFu's tracker. Ain't that cool?
Certain thanks must be given to MonkeyQuest, which motivated me to write this by being everything that I wanted in a quest-tracker replacement while annoying me by putting a frame over a quarter of my screen.