Rustical is an open-source CalDAV and CardDAV server written in Rust, providing a lightweight, self-hosted alternative for calendar and addressbook synchronization. It implements the core WebDAV extensions (RFC 4791, 6352) with support for CalDAV scheduling, CardDAV group membership, WebDAV Push (web-push) notifications, and a built-in web frontend for management. The architecture is a modular Rust workspace with separate crates for DAV infrastructure, protocol handlers (caldav, carddav), storage abstraction, SQLite backend, XML serialization, OIDC authentication, and a Lit-based web UI. The server exposes RESTful HTTP endpoints via Axum, uses SQLite for persistence with `sqlx`, and supports app tokens, OIDC, and Nextcloud login for authentication. The codebase demonstrates solid engineering with thorough integration tests, snapshot testing, CI/CD pipelines, and a clear separation of concerns. However, it contains some workarounds and TODOs indicating active development rather than a polished final product. The custom XML derive macros and store trait pattern are particularly well-crafted and potentially reusable.