Tales and Chronicles
Jewel of the North, formerly know as vincegetorix
I use them mostly like tools' proficiencies: if a PC tries a skill test and also use their proficiency with X language, I grant them advantage if it makes sense (History check to decipher old elvish stuff, persuading a goblinoid, spotting the lies of a gnome etc).Just out of curiosity, does language actually come up in everyone's game? I've used it but only written languages, like trying to translate a dead language no longer used.