Neptune

Neptune is a peer-to-peer anonymous cash protocol featuring privacy, scalability, and post-quantum security. To our knowledge, it is the first blockchain protocol to integrate zk-STARKs on Layer-1 (where they belong). It is definitely the first blockchain protocol to feature mutator sets, a novel solution for achieving privacy without sacrificing scalability. As a cherry on top, Neptune also supports arbitrary logic; together with privacy, this support makes Neptune a private smart contract platform in addition to a competitor for the world's best possible money.