This repository is the source code for NGINX, a production-grade web server, reverse proxy, load balancer, API gateway, and mail proxy. The codebase is written entirely in C and is a definitive example of high-performance systems architecture. It employs a modular, event-driven, multi-process (master/worker) model. The core infrastructure is built around a set of highly optimized, self-contained data structures and utilities: a slab allocator for shared memory, a memory pool for request-scoped allocation, a red-black tree for timers and caches, a radix tree for IP routing, a hash table with wildcard support for server name matching, and an incremental JSON parser. The build system (auto/) is a sophisticated set of shell scripts that handle platform detection, dependency configuration, and module compilation. The code supports HTTP/1.x, HTTP/2, HTTP/3 (QUIC), TCP/UDP proxying (Stream module), and mail protocols (POP3, IMAP, SMTP). It is actively maintained, with a strong focus on performance, stability, and security. The code is exceptionally clean and well-structured for a project of its age and complexity, though it contains some platform-specific #ifdef sprawl and duplication between HTTP and Stream modules (e.g., upstream least_time, map).
Boost.Beast is a production-grade C++ library providing asynchronous HTTP/1.1 and WebSocket client/server implementations. Built on the Boost.Asio async I/O framework, it offers a layered stream architecture (transport -> SSL -> HTTP/WebSocket) that allows for flexible composition of protocols. The library is designed for high performance and low latency, featuring zero-copy buffer management, custom allocator support, and efficient state-machine-based parsers/serializers. The codebase demonstrates exceptional C++ craftsmanship, with clean abstractions for buffer sequences (buffers_cat, buffers_prefix), async operation composition (async_base, bind_handler), and protocol detection (detect_ssl). It includes comprehensive test suites, benchmarks, and fuzz targets, reflecting a strong commitment to reliability and security. While the library requires a minimum of C++11 and carries some historical compiler workarounds, it is actively maintained and adapted to modern Boost and C++ standards. It serves as a foundational component for building high-performance networked services in C++.
Certd is a full-stack web application that automates the entire lifecycle of SSL/TLS certificates, from application via the ACME protocol to deployment across 110+ cloud providers, CDNs, and hosting platforms. It utilizes a pipeline engine for orchestrating multi-stage tasks (cert apply, conversion, deploy, notification) with retry, skip-on-success, and cron/webhook triggers. The system features a plugin architecture with decorator-based registration for tasks, access credentials, DNS providers, notifications, and OAuth, making it highly extensible. The monorepo includes a Vue 3 + Vben admin frontend and a Midway.js (Koa) backend with TypeORM and multi-database support (SQLite, MySQL, PostgreSQL). It also supports commercial features like subscription plans, wallet, payments, and enterprise project isolation. While the codebase is well-structured and actively maintained, the large number of cloud provider plugins and legacy auto-generated SDKs (e.g., JDCloud) introduce maintenance overhead and potential API drift.