1. developer tooling and libraries

halo2 has benefited from an incredible range of community-built developer tooling.

frontends and interfaces

• halo2repl: a web browser interface to write halo2 circuits with Javascript bindings for halo2-lib.

domain-specific languages

• Chiquito: a high-level structured language for implementing zero knowledge proof applications that compiles to the halo2 backend.
• powdr: an extended polynomial identity (PIL) and zk-focused assembly (zkASM) language written in Rust, focused on modularity and excellent developer experience. Supports halo2 backend.
• zkas (DarkFi): a toolchain consisting of a lexer, parser, static and semantic analyzers, and a binary code compiler.

libraries

• halo2wrong: applications involving non-native arithmetic
• halo2-lib: primitives for writing circuits, including
  • halo2-base: an API using a simple vertical gate;
  • halo2-ecc: elliptic curve cryptography primitives
• tachyon: accelerated library using CUDA

other primitives

• halo2-rsa (zk-email): RSA verification circuit
• halo2-regex (zk-email): regex verification circuit
• halo2-base64 (zk-email): base64 decoding circuit

formal verification

• Automated Analysis of Halo2 Circuits [Soureshjani et al, 2023]: detecting under-constrained halo2 circuits using an SMT solver.
  • implementation: quantstamp/halo2-analyzer