Awesome
Awesome HALO2 
A community-maintained list of halo2-related resources. Feel free to PR.
Join the community Discord at: https://discord.gg/GEJX7SfEuh
Also check the fantastic https://halo2.club coordinated by @therealyingtong
Protocol
Projects
- Zcash Protocol NU5: Orchard
- Ethereum Foundation zkEVM
- Scroll zkEVM
- Taiko zkEVM
- Deep Learning in Halo 2
- DarkFi zk assembler and VM
- Eigen Trust - A distributed reputation system
- Axiom Zk processor - provides smart contracts trustless access to historic on-chain data and arbitrary expressive compute
- DelphinusLab's zkWASM
- Proof of solvency
Gadgets
- ECC's Halo2 gadgets includes Sinsemilla, Similla ECC, SHA256, Poseidon
- PSE's halo2wrong includes field emulation, generic ECC & ECDSA
- PSE's pairings
- Scrolltech Halo2 aggregator
- Semaphore
- DarkFi Halo2 gadgets includes arithmetic, comparisons, and range checks
- nikkolasg's Verkle tree
- DrPeterVanNostrand's Merkle tree
- RSA verification circuit
- halo2-lib, a library of basic gadgets for halo2 development
- verifiable encryption based of the hashed ElGamal scheme
- DelphinusLab's BN256 and BLS12-381 pairings
- FRI verifier
- Rate limit nullifier
- halo2-utils
Educational
- Orbis Labs' TinyRAM implementation
- Halo and more: exploring incremental verification and SNARKs without pairings
- Sin7Y, Halo Principle Explained
- Sin7Y, Sin7Y Tech Review: Develop Circuits Using Halo 2
- Darkrenaissance's sage implementation
- ZK Meetup Seoul, Deep dive on Halo2 2020
- Zcash: Halo 2 and SNARKs without Trusted Setups 2021
- ZK7: Latest developments in Halo2 2022
- Halo2 tutorial source
- Building a Zero Knowledge web app with Halo 2 and Wasm
Others
- Arithmetization of Functional Program Execution via Interaction Nets in Halo 2
- Arithmetization of ∑¹₁ Relations in Halo 2
- Zordle is Wordle, but with zero-knowledge proofs, uses wasm
- Hammster proves Hamming distance in zk, also uses wasm
- Vocdoni anonymous voting (wasm)
- Sice HALO2 is PLONK-based see awesome-plonk
- Zkbitcoin halo2 test suite, uses wasm