// the find
mozilla/neqo
Neqo, the Mozilla Firefox implementation of QUIC in Rust
Neqo is Mozilla's production QUIC and HTTP/3 implementation in Rust, shipping inside Firefox. If you want to understand how a real-world QUIC stack is built and tested, this is the reference — it's not a toy or a demo.
The CI setup is exceptional: mutation testing, fuzzing with committed corpus, QUIC interop runner tests against other implementations, sanitizer runs, and CodSpeed benchmarking all run on PRs. The QLOG support with qvis integration makes debugging packet flows actually tractable. NSS as the TLS backend means it shares the same crypto code as Firefox, so any TLS bugs get fixed across the whole Mozilla stack at once. The patch release workflow (long-lived vX.Y branches, Bugzilla integration, supply-chain audits via cargo-vet) shows what production-grade Rust release management looks like.
NSS is the TLS backend, not rustls or ring, which means building it requires Mercurial, GYP, and Ninja — a painful dependency chain that has nothing to do with Rust. The server side is explicitly experimental and not production-hardened, so this is really a client library with a test server attached. The codebase is tightly coupled to Firefox's internal needs (neqo_glue, Gecko integration) which shapes API decisions in ways that won't match your use case if you're not Mozilla. Documentation for embedding it outside of Gecko is thin; you're expected to read the source and the Firefox integration code.