MACI

ZK Email provides circuits and SDKs for proving facts about redacted email transcripts onchain. Useful when you want privacy-preserving identity or receipt checks without doxxing inboxes.

SP1 from Succinct is a zero-knowledge virtual machine that proves correct execution of RISC-V programs, and it is used to generate proofs for rollups and bridges. Teams compile a Rust program with it when a proof must stand in for re-executing that program onchain.

arkworks algebra is a set of Rust libraries for finite field, elliptic curve, and polynomial arithmetic, and it is the math layer under many SNARK and STARK toolchains. Rust builders add the ark crates when writing proving code from the ground up.