OKCash is a Proof of Stake cryptocurrency that was released under the MIT licence.

WhiteCoin is a cryptocurrency protocol with a Proof-of-Stake (PoS) consensus mechanism. WhiteCoin's (XWC) marketing materials place an emphasis on security and stability, but do not present details regarding their specific technical advantages or project goals.
WhiteCoin's payment network provides a high degree of anonymity and its PoS consensus model allows XWC coin holders to earn revenue by staking their holdings.

Nasdacoin is developing a blockchain with a hybrid consensus mechanism that combines elements of Proof-of-Work (PoW) and Proof-of-Stake (PoS). Nasdacoin uses the Scrypt hashing algorithm and is powered by the NSD coin. The company plans on developing a comprehensive ecosystem with a native exchange, wallet, App, and marketplace. They also plan on allowing Nasdacoin holders to transfer their NSD balance to a Visa card that can be used anywhere.