I had to do this for you. I couldn't look at it the way it was:

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Aboleth
Abyssal
Aquan
Auran
Beholder
Buommi
Celestial
Common
Diabolan (Dragon Compendium)
Draconic
Drow Sign Language
Druidic
Dwarven
Elven
Feline
Ghost Elven (combination of Infernal and Elven, more or less)
Giant
Gith (Githyanki and Githzerai are technically different languages)
Gnoll
Gnome
Goblin
Gol-Kaa (Goliath)
Grell (half verbal, half electrical impulses)
Halfling
Ignan
Illumian
Infernal
Kuo-toa
Lupin (likewise)
Maenad
Modron
Mongrel
Neraph
Orc
Qualith (written only, Mind Flayer)
Rhek
Shadowswyft
Silthilar
Slaad
Sylvan
Terran
Thri-Kreen
Tsochar (primarily written)
Tuilvalanuue (Raptoran)
Undercommon (Drow, Mind Flayers, etc)
Xeph