Zcoin is a privacy coin based on Bitcoin Core and the first project to implement the Zerocoin protocol for private transactions using zero-knowlege proofs. Its use case is that of a currency enabling private payments and other financial transactions. Another focus is on decentralisation. This is why Zcoin is currently working on developing a new memory-hard PoW algorithm called Merkle Tree Proofs (MTP) that levels the playing field in mining and enables more people to mine which is important for fair distribution. The project did not have an ICO but is backed by investors like Time Lee and Roger Ver.