Radicale is a production-grade CalDAV and CardDAV server implemented in Python. It provides a self-hosted solution for managing calendars, address books, tasks, and journals via standard WebDAV, CalDAV, and CardDAV protocols. The system supports multi-user, multi-collection setups with pluggable backends for authentication (htpasswd, LDAP, IMAP, OAuth2, PAM, Dovecot, remote_user), storage (multifilesystem with caching), rights management, sharing (token/map-based), and web UI. It includes a built-in HTTP/HTTPS server with WSGI compatibility, a browser-based management interface, and extensive configuration options for security, performance, and integration with reverse proxies. The architecture follows a modular plugin pattern: each major subsystem (auth, storage, rights, web, hook, sharing, group) defines a base class and is loaded dynamically via a plugin loader. The core application dispatches HTTP requests through a WSGI application class that handles authentication, locking, logging, and profiling. The storage layer uses a mixin-based design to separate concerns (cache, sync, history, lock, etc.) and stores collections as filesystem directories with individual item files. The sharing module provides a REST API for managing shares, including VCF-to-ICS birthday conversion and property overlays. Key features include CalDAV filtering and recurrence expansion, sync-token support, free-busy reports, email notifications via hooks, and a JavaScript frontend for collection and sharing management. The codebase is well-tested with both unit tests (Python) and integration tests (Playwright), and includes CI/CD pipelines for multi-architecture Docker images and PyPI publishing. While primarily an application, it contains reusable data processing logic for iCalendar/vCard parsing and transformation.
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.
This repository is a .NET library (Ical.Net) that implements the iCalendar specification (RFC 5545) for parsing, manipulating, and serializing calendar data in the ICS format. It provides core types such as Calendar, CalendarEvent, Todo, Journal, FreeBusy, VTimeZone, and Alarm, along with comprehensive support for recurrence rules (RRULE, RDATE, EXDATE), time zone handling via NodaTime, and free/busy computation. The architecture follows an object-oriented design with clear separation of concerns: data types (e.g., CalDateTime, Period, RecurrenceRule), calendar components, serializers (e.g., CalendarSerializer, PropertySerializer), and an evaluation engine for expanding recurring occurrences. The library is production-grade, with extensive test coverage (including a large corpus of ICS fixture files and regression tests for bug fixes), benchmarks for performance, and a logging abstraction. It is not a standalone application but a library designed to be consumed by .NET applications that need iCalendar functionality.