Hacker News Reader

Many QUIC features get implemented while in draft stage as people iterate on the RFC's design (e.g., ACK Frequency[0] is currently on draft version 14 and I implemented support for it three years ago in quinn).

[0]: https://datatracker.ietf.org/doc/html/draft-ietf-quic-ack-fr...

It’s pretty common for IETF drafts to be substantially complete well before they are finalized as RFCs. For example, supporting ML-KEM in TLS is still a draft, but there are already multiple large scale deployments of it since the technical aspects were nailed down a while ago

It’s common enough for groups to not consider the spec done until there is a decent bit of implementation experience (both because actual implementers tend to find interesting bugs in specs, and because many things are hard to measure without any implementation).

> I guess it's common to have the implementation foreshadowing the RFC

"Rough consensus and running code" is the IETF's unofficial motto. Working Group Drafts are generally accompanied by implementations.

It's been a draft for a long while, and was only recently approved