Maithili has what few Indian regional languages have kept: a script of its own. Tirhuta, also called Mithilakshar, is a sister of Bengali and Assamese script and was in ordinary use for manuscripts and land records into the twentieth century. It is now used mainly ceremonially and in a deliberate revival. Maithili itself was added to the Eighth Schedule of the Indian Constitution in 2003, after a long campaign, and is the second-most spoken language of Nepal.
Standard MaithiliIndo-Aryan, Eastern (Bihari group)
The Darbhanga–Madhubani register, the basis of the literary language and of the Sahitya Akademi's Maithili canon.
बोलने वाले: About 1.35 crore in India in the 2011 Census, and roughly 3 million in Nepal
BajjikaIndo-Aryan, Eastern (Bihari group)
Spoken in Muzaffarpur, Vaishali, Sitamarhi and East Champaran — between Maithili and Bhojpuri, claimed by both, and counted as Hindi in the census.
Kosi MaithiliIndo-Aryan, Eastern
The eastern variety of Saharsa, Supaul and Madhepura, shading towards Angika beyond the Kosi.
Nepali MaithiliIndo-Aryan, Eastern
Spoken across Nepal's Madhesh province; standardised separately, written in Devanagari, and politically far more assertive than its Indian counterpart.