Censorship decides in the opening of the flow. So we made the opening the whole game.
Opening Book is an approach to internet censorship circumvention built on one fact: a modern censor classifies each connection from the opening of the flow — the TLS ClientHello, the server name, the JA3/JA4 fingerprint, the sizes and timing of the first few packets — then applies a policy. For many systems that opening verdict is the whole story.
So the leverage is entirely in the opening. Opening Book is an evolving, portable repertoire of opening moves ("gambits"): shape the ClientHello, its record framing, and its segment/timing — anchored at a genuine Chrome handshake, expressed as a signed parameter set that runs on two engines (BoringSSL in Rust, uTLS in Go), and discovered against the live network with a server-side fitness signal.
The site (a deep-dive into the approach): https://getlantern.github.io/opening-book/
This is a research direction from the team behind Lantern, not a product spec. Specific live strategies are deliberately omitted — the repertoire is meant to be polymorphic and ever-changing; this describes the approach, not the moves currently on the board.
The site is a single self-contained index.html (no build step), served by GitHub Pages.