Lightning Bitcoin is a cryptocurrency protocol with a DPoS consensus mechanism. It is a hard fork of Bitcoin that was created with the goal of improving transaction speeds and scalabilty. Lightning Bitcoin's on-chain governance system enables LBTC holders to vote for the blockchain improvement proposals and the delegates who maintain the network as Lightning Nodes. Lightning Bitcoin is not related to the Lighting Network, which is an off-chain protocol built on the Bitcoin blockchain.

ZCoin is a privacy focused cryptocurrency built on Ethereum. The ZCoin protocol enables anonymous transactions with cryptography that utilizes Zero-Knowledge Proofs (ZKP). ZCoin increases privacy on their network by using a coin-mixer contract that wraps transactions in a serial number and destroying wrapped coins once they have been redeemed.
Zcoin was the first cryptocurrency to use a Merkle Tree Proof (MTP) as its proof of work algorithm. Merkle Tree Proofs are an innovative solution to achieving network consensus, and can increase transaction time while reducing the centralizing tendency of ASIC mining.

Bitcoin Cash is a cryptocurrency that was created as a result of a hard fork of the original Bitcoin blockchain that took place in 2017. Due to the open source nature of the Bitcoin protocol, and the lack of a central governing body to resolve disputes, the Bitcoin community became extremely divided about what to do about rising fees and slow transaction times. As the platform's transaction volume increased, and the associated fees to confirm them also increased dramatically, many people began advocating for a larger block size.
In mid 2017, a group of developers introduced segregated witness technology, or SegWit, that was designed to increase Bitcoin's scalability by moving some transaction details off of the blockchain. Segwit was meant to resolve the issues that revolved around the growing amount of transaction data, but many members of the Bitcoin community felt that it undermined the original vision outlined by Satoshi Nakamoto.
On August 1, 2017, they initiated a hard fork of the protocol that created Bitcoin Cash and implemented an increased block size of 8mb. At the time of the fork, bitcoin holders automatically became owners of the same number of Bitcoin Cash units. The increased block size led to faster transaction times and made Bitcoin Cash easier to use as a medium of exchange.