Action Bar Mods Addons that create or modify action bars/secure buttons and addons related to them.
Auction House Mods for the Auction House
Bags, Bank, Inventory Mods Addons that modify the look and feel of your bags and bank, or modify how you handle your inventory, loot, etc.
Buff/Debuff/Spell Mods Addons which alter the display of buffs/debuffs, monitor for buffs/debuffs/items, etc.
Casting Bars and Cooldowns Addons that modify or replace the cast bar, target/focus/party cast bars, cooldown timers/alerts, swing timers, etc.
Chat Mods Anything that modifies the chat window, chat output, etc
Class Specific (sub-categories) Mods that are designed for a specific class
Combat Mods These addons deal with combat itself – dps meters, warnings, feedback, kill logs, and anything that parses the combat log.
Data Mods Any addon that gathers data to be exported or provides databases for use in-game (loot database, vendor price database, boss drop database, etc.).
Graphic UI Mods These addons alter the way you view your interface. Moving elements of the UI, changing fonts, adding art panels, skinning various elements, altering the presentation/look/layout of default frames, etc.
Group/Guild Mods that provide functions for groups/guilds to use (calendars, communication, etc.)
Info/Plug-in Bars (sub-categories) Eg: Data Broker, FuBar, Titan Panel, etc.
Map Mods, coords/compasses Anything that alters the world map or minimap (scale, transparency, map notes, gathering aids, etc.), coordinate displays, compasses.
Mail These addons alter the look and feel of the mailbox.
Mini Games/ROFL Mods to amuse you
PvP/Arena/BattleGrounds These addons are made for arenas/battlegrounds, pvp play, and the display of information dealing with those elements.
Quest/Leveling/Reputation Mods These addons alter the look and feel of the quest log, provide alternate quest tracking methods, and provide features to aid in players questing with one another.
Raid Mods Raid frame enhancements or replacements, raid cooldown monitors, loot system addons, main tank frames, and anything else having to do with raiding.
RolePlay, Music Mods Addons for the serious role player, or just those that wish to add a little flair via text/sound. Also in-game music players.
TradeSkill Mods Mods that are designed specifically for Tradeskills
ToolTip Addons which alter the look and feel or placement of the tooltip itself.
Unit Mods Player/pet/target/party unit frame modifications or replacements, HUDs, etc.
Miscellaneous Anything that doesn't quite fit anywhere else
