Xeer - read "The Law of the Somalis"

Pastunwali is similar, but in southern Afghanistan, any time there's nobody physically present trying to enforce Shariah at gunpoint

Original-flavour Common Law was very close.

Merchant Law in medieval Europe.

Rural South Asia and East Africa today mostly run on traditional courts of various local flavours. Often the central fiat governments try to repress them and stamp them out, but traditional freedoms die hard.