Calendaring Systems Developers Resources and Tools

This is a list of developer's tools, libraries, and other resources of particular interest to calendaring systems developers but excluding testing (see below). We would be please to either provide a link to resources suggested by any interested party, or if you desire we would be happy to put the material on our own site. We actively solicit suggestions and contributions for this page; please send any contributions to Please be sure to give us the necessary information for this page: name of the resource/tool/library, link, author's name if possible, and a (very) brief description.

(A list of tester's resources, including test suites and performance tools, may be found at Testing Resources.)

Building CalDAV and CardDAV Clients

These documents on building a CalDAV or a CardDAV client are intended for developers. While they reference SabreDAV the guides are sufficiently general to be readily applied for any CalDAV or CardDAV server.

From Evert Pot, June, 2014

Starter List of CalDAV and CardDAV Standards and Specifications:

This page is intended for individuals who wish to develop a CalDAV or CardDAV server but who have no previous experience with the specifications. It offers a basic list of (and links to) specifications or parts of specifications with which you need to become familiar.

This page was originally named "Getting Started with CalDAV and CardDAV" but the name was changed to more accurately reflect the content; the previous URL is aliased to this page.

CalDAV Protocol Site Libraries and Tools:

The CalDAV Protocol site offers lists of clients, servers, services, and libraries and tools for CalDAV.

CardDAV Protocol Site Libraries and Tools:

The CardDAV Protocol site offers lists of clients, servers, services, and libraries and tools for CardDAV.


Javascript parser for ics files (RFC 5545). From Philipp Kewisch, February 2013.

iCalendar Validator:

The iCalendar Validator is used to validate calendaring data against the iCalendar (RFC 5545) standard. These tools can be used by producers of iCalendar data to help ensure your iCalendars are standards-compliant, and by consumers of iCalendar data to check for possible errors in the iCalendars they receive. Please send any errors, corrections, or clarifications in the validator to From Doug Day, April 2010.


Milton is a java library for WebDAV, CalDAV and CardDAV server implementations. From Brad McEvoy, February 2013.