neqo

neqo is Mozilla's implementation of QUIC and HTTP/3 written in Rust, the same code that powers networking inside Firefox. QUIC is a faster, more reliable replacement for TCP, the protocol most internet traffic still rides on, and HTTP/3 is the newest version of the web protocol built on top of it. neqo gives you QUIC transport, HTTP/3, and QPACK header compression as Rust libraries, dual-licensed under Apache 2.0 and MIT.

This is not an app you install. It's library code you compile into your own networking software, plus a couple of command-line tools for testing HTTP/3 clients and servers. Using it means working at the protocol level in Rust, deep specialized engineering, not a weekend integration.

Who is this for: teams building browsers, networking stacks, or protocol-level tooling who need a real QUIC implementation and want Mozilla's. Everyone else almost certainly wants a higher-level library like quinn instead. There is no paywall and no team-size split, since it's a building block, not a product.

The catch: Mozilla flat out says the server side is experimental and warns against running it in production. The client and transport are battle-tested inside Firefox, but treat the server code as a lab tool, not something you put in front of real traffic.