GoByte (GBX) is a cryptocurrency based on Dash aimed at vendors to provide monetary services . GoByte features the masternode technology, which provides to the network near-instant and secure payments as well as anonymous transactions. The near-instant payments known as InstantSend technology, average at 1.3 seconds per transaction. The anonymous transactions known as PrivateSend technology, mix your funds through the masternodes network, making near-impossible to trace back the origin of the funds.
Zcoin is the first full implementation of the Sigma Protocol, which allows users to have complete privacy via zero-knowledge cryptographic proofs. It is worth noting that Zcoin is unrelated to other cryptocurrencies utilizing the Zerocash Protocol. Although Zerocash is a development from Zcoin’s old protocol Zerocoin, their respective implementations are not simple forks of each other, but rely on different cryptographic assumptions with various tradeoffs. Both approaches supplement each other quite nicely, and a good way to describe them would be sibling projects.