[A]lternative [B]lockchains and [C]ryptocurrencies is a group for people interested in different alternatives in the blockchain space. Optimal levels of anonymity (privacy), speed, governance, energy consumption. These, and other relevant questions are approached technically from a computer science point of view, mathematically, or entirely philosophically. Economics plays a big role in these discussions as cryptocurrencies are taking a serious foothold in many ecosystems.