Bitcoin is a cryptocurrency. It is a decentralized digital currency without a central bank or single administrator that can be sent from user to user on the peer-to-peer bitcoin network without the need for intermediaries.
Litecoin is a peer-to-peer cryptocurrency and open-source software project released under the MIT/X11 license. Creation and transfer of coins is based on an open source cryptographic protocol and is not managed by any central authority.
Namecoin is a cryptocurrency originally forked from bitcoin software. It is based on the code of bitcoin and uses the same proof-of-work algorithm. Like bitcoin, it is limited to 21 million coins.
Namecoin can store data within its own blockchain transaction database. The original proposal for Namecoin called for Namecoin to insert data into bitcoin's blockchain directly.
Peercoin, also known as PPCoin or PPC, is a peer-to-peer cryptocurrency utilizing both proof-of-stake and proof-of-work systems.
Peercoin is based on an August 2012 paper which listed the authors as Scott Nadal and Sunny King. King, who also created Primecoin, is a pseudonym. The Peercoin source code is distributed under the MIT/X11 software license.
In the proof-of-stake system, new coins are generated based on the holdings of individuals. In other words, someone holding 1% of the currency will generate 1% of all proof-of-stake coin blocks. This has the effect of making a monopoly more costly, and separates the risk of a monopoly from proof-of-work mining shares.
Dogecoin is a cryptocurrency featuring a likeness of the Shiba Inu dog from the "Doge" Internet meme as its logo. Introduced as a "joke currency" on 6 December 2013, Dogecoin quickly developed its own online community and reached a capitalization of US$60 million in January 2014.
Monero is an open-source cryptocurrency created in April 2014 that focuses on fungibility, privacy and decentralization. Monero uses an obfuscated public ledger, meaning anybody can broadcast or send transactions, but no outside observer can tell the source, amount or destination.
Titcoin is a type of digital currency called a cryptocurrency that uses pornography on a decentralized peer-to-peer network to manage the issuance of new currency units while simultaneously processing transactions.
Stellar is an open source, decentralized protocol for digital currency to fiat money transfers which allows cross-border transactions between any pair of currencies. The Stellar protocol is supported by a 5013 nonprofit, the Stellar Development Foundation.