So, under this protocol, a coin is destroyed and then minted again to erase the past history of the coin?
While a coin is spent, there is no information available which reveal exactly which coin is being spent. Initially, the zerocoin protocol was planned to be integrated into the Bitcoin network.
However, the proposal was not accepted by the Bitcoin community. Thus, the zerocoin developers decided to launch the protocol into an independent cryptocurrency.
As I know, they want to create a standalone cryptocurrency implementing the zerocoin protocol and it was named "Moneta". THen in September 2016, Zcoin, the first cryptocurrency to implement the zerocoin protocol, was launched by Poramin Insom and team.