Difference between Monero, Dash and Zcash I'm curious to understand what  the main differences between Monero, DASH and to-be released Zcash are. I would also like to know what is the main improvement in Zcash, when compared to Dash and Monero.
Monero - A cryptocurrency that uses ring signatures, a type of cryptography that enables untraceable transactions.  It is extremely unlikely that a transaction can be traced to a particular user. Monero is based on the CryptoNote protocol and possesses significant algorithmic differences relating to blockchain obfuscation

DASH - rebranded from "Darkcoin" to "Dash" on March 25, 2015. Dashcoin is an anonymous cryptocurrency and the first automatically mutating cryptocurrency created with CryptoNote technology. It offers instant transactions (InstantSend), private transactions (PrivateSend) and token fungibility.

ZCash - is said to offer total payment confidentiality while still maintaining a decentralized network that runs on public blockchain.  Zcash transactions hide the sender, receiver, and transaction value.  One must have the correct view key in order to see a transaction. This cryptocurrency uses zk-SNARK, which allows a network to have a secure ledger of transactions without making the parties and amounts transferred public.