(From the wikipedia page)
Dash (formerly known as Darkcoin and XCoin) is an open source peer-to-peer cryptocurrency that offers instant transactions (InstantSend), private transactions (PrivateSend) and token fungibility. It was rebranded from "Darkcoin" to "Dash" on March 25, 2015, a portmanteau of "Digital Cash". Dash operates a decentralized governance and budgeting system, making it the first decentralized autonomous organization. Dash uses a chained hashing algorithm called X11 for the proof-of-work. Instead of using the SHA-256 (from well-known Secure Hash Algorithm family) or scrypt it uses 11 rounds of different hashing functions. As of 2016, Dash is among the top-5 most popular cryptocurrencies.