3. Litecoin (LTC)

Litecoin, released via an open-source client on GitHub on October 7, 2011 by Charlie Lee, 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. While inspired by, and in most regards technically nearly identical to Bitcoin (BTC), Litecoin is far quicker and cheaper.
Till Dec. 21st, 2017, about 54.39 million LTC have been mined with a total market cap of about 17.4 billion dollars, ranking 5th in global cryptocurrency market capitalizations.

Litecoin official website:https://litecoin.org/
Litecoin blockchain:http://explorer.litecoin.net/