WireGuard

Official docs outline

Quick Start and interface setup
Creating key pairs, configuring wg0 interfaces with ip and wg, and bringing up a tunnel between peers.
Cryptokey routing
How public keys bind to AllowedIPs lists, deciding outgoing routing and incoming source filtering per peer.
Conceptual overview and roaming
Peers, endpoints, roaming, the UDP-based stateless interface model, and built-in roaming.
Protocol and cryptography
Noise IK handshake, Curve25519, ChaCha20-Poly1305, BLAKE2s, rekeying, and cookie-based DoS mitigation.
Network namespace integration
Moving the WireGuard interface across Linux network namespaces to build container and VPN isolation.
wg and wg-quick tools
Config file format, Interface and Peer sections, PostUp/PostDown hooks, and the wg and wg-quick commands.
Performance
Throughput and latency characteristics of the in-kernel implementation and benchmark methodology.
Known limitations
Constraints such as no built-in dynamic IP assignment, TCP-over-UDP caveats, and key management left to the operator.
Whitepaper
Formal design of the protocol, its security properties, timers, and DoS resistance.

Each section links to the official page. Titles and summaries by Extra Credit; the docs belong to their authors.