BigDebuffs is an extremely lightweight addon which replaces unit frame portraits with auras, stances and interrupts whenever present.
The addon menu can be accessed by typing /bd or /bigdebuffs.
To download this addon, hit the green "Code" button and then select Download ZIP.
Once the addon is finished downloading, extract the contents to your Interface/AddOns directory and importantly rename the folder from BigDebuffs-WoTLK-master to BigDebuffs.
The backport is based on BfA BigDebuffs. However, the backport does not contain any raid frame modifications (number of debuffs shown / crowd control effects) since the new raid frames do not exist in WotLK (they were implemented in Cataclysm). The backport is essentially a much improved version of LoseControl.
Contributions
I'd like to thank the following people for their contributions to this release:
Jordon for the base addon, as developed throughout MoP-BfA (and possibly further).
Jakeswork for his completion of the WotLK aura list, minor bug fixes and the Warrior stance logic addition.