The Bitcoin Wars is a series focused primarily around Bitcoin, but also other digital currencies and their effects on the world, written by Mathew Crawford at Rounding the Earth. He is now keeping track of interesting Bitcoin history and information in his Bitcoin graph.
Bitcoin may be the most important development in digital ledger technology, but there are other cryptocurrencies, which are digital units swapped around digital ledger systems.
The term “alt coin” refers to cryptocurrencies aside from Bitcoin itself.