Since the initial success of Bitcoin, many alternative currency projects have been launched. Bitcoin was released in 2009, and the first alternative coin project (named Namecoin) was introduced in 2011. In 2013 and 2014, the alternative coins (altcoin) market grew exponentially, and many different types of alternative coin project were started.
A few of those became a success, whereas many were unpopular due to less interest and as a result, they did not succeed. A few were pump and dump scams that surfaced for some time but soon disappeared. Alternative approaches to Bitcoin can be divided broadly into two categories, based on the primary purpose of their development. If the primary goal is to build a decentralized blockchain platform, they are called alternative chains; if the sole purpose of the alternative project is to introduce a new virtual currency, it is called an altcoin.
Alternative blockchains are discussed in detail in this book's bonus...