sabre/dav

sabre/dav is a PHP library for implementing WebDAV, CalDAV, and CardDAV servers. It provides the protocol handling, routing, and interoperability layers needed to expose files, calendars, and address books to standard clients while letting you plug in your own storage and authentication.

Key Features

• WebDAV server framework with support for common clients (e.g., Windows/macOS/WebDAV tools)
• CalDAV (calendar) and CardDAV (contacts) protocol implementations for sync to desktop/mobile clients
• Pluggable architecture (server “plugins”) for adding features such as authentication, ACL, locks, sync reports, etc.
• Backend abstraction: implement interfaces to connect calendars/contacts/files to your database or filesystem
• Standards-focused design with broad RFC coverage and strong emphasis on interoperability
• Ships as a Composer package for embedding into custom PHP applications

Use Cases

• Add CalDAV/CardDAV sync (calendars/contacts) to an existing PHP product
• Provide a WebDAV endpoint for document access/editing from desktop/mobile clients
• Build a lightweight groupware sync layer backed by custom storage and auth

Limitations and Considerations

• It is a developer-focused library rather than a complete “ready-to-run” end-user server; you typically need to implement storage backends and deploy within your own PHP application.

sabre/dav is best suited when you need standards-compliant DAV capabilities inside a PHP stack and want control over authentication, data models, and persistence. Its plugin system and backend interfaces make it adaptable to many architectures while retaining protocol correctness.