WebDAV (Web Distributed Authoring and Versioning) is a set of extensions to the Hypertext Transfer Protocol (HTTP), which allows

user agent On the Web, a user agent is a software agent responsible for retrieving and facilitating end-user interaction with Web content. This includes all web browsers, such as Google Chrome and Safari A safari (; originally ) is an overland jour ...

s to collaboratively author contents ''directly'' in an HTTP web server by providing facilities for

concurrency control In information technology and computer science, especially in the fields of computer programming, operating systems, multiprocessors, and databases, concurrency control ensures that correct results for concurrent operations are generated, whil ...

and namespace operations, thus allowing the Web to be viewed as a ''writeable, collaborative medium'' and not just a read-only medium. WebDAV is defined in by a

working group A working group is a group of experts working together to achieve specified goals. Such groups are domain-specific and focus on discussion or activity around a specific subject area. The term can sometimes refer to an interdisciplinary collab ...

of the

Internet Engineering Task Force The Internet Engineering Task Force (IETF) is a standards organization for the Internet standard, Internet and is responsible for the technical standards that make up the Internet protocol suite (TCP/IP). It has no formal membership roster ...

(IETF). The WebDAV protocol provides a framework for users to create, change and move documents on a server. The most important features include the maintenance of properties about an author or modification date,

namespace In computing, a namespace is a set of signs (''names'') that are used to identify and refer to objects of various kinds. A namespace ensures that all of a given set of objects have unique names so that they can be easily identified. Namespaces ...

management, collections, and overwrite protection. Maintenance of properties includes such things as the creation, removal, and querying of file information. Namespace management deals with the ability to copy and move web pages within a server's namespace. Collections deal with the creation, removal, and listing of various resources. Lastly, overwrite protection handles aspects related to the locking of files. It takes advantage of existing technologies such as

Transport Layer Security Transport Layer Security (TLS) is a cryptographic protocol designed to provide communications security over a computer network, such as the Internet. The protocol is widely used in applications such as email, instant messaging, and voice over ...

, digest access authentication or

XML Extensible Markup Language (XML) is a markup language and file format for storing, transmitting, and reconstructing data. It defines a set of rules for encoding electronic document, documents in a format that is both human-readable and Machine-r ...

to satisfy those requirements. Many modern

operating system An operating system (OS) is system software that manages computer hardware and software resources, and provides common daemon (computing), services for computer programs. Time-sharing operating systems scheduler (computing), schedule tasks for ...

s provide built-in client-side support for WebDAV.

History

WebDAV began in 1996 when Jim Whitehead worked with the

World Wide Web Consortium The World Wide Web Consortium (W3C) is the main international standards organization for the World Wide Web. Founded in 1994 by Tim Berners-Lee, the consortium is made up of member organizations that maintain full-time staff working together in ...

(W3C) to host two meetings to discuss the problem of distributed authoring on the

World Wide Web The World Wide Web (WWW or simply the Web) is an information system that enables Content (media), content sharing over the Internet through user-friendly ways meant to appeal to users beyond Information technology, IT specialists and hobbyis ...

with interested people.

Tim Berners-Lee Sir Timothy John Berners-Lee (born 8 June 1955), also known as TimBL, is an English computer scientist best known as the inventor of the World Wide Web, the HTML markup language, the URL system, and HTTP. He is a professorial research fellow a ...

's original vision of the Web involved a medium for both reading and writing. In fact, Berners-Lee's first

web browser A web browser, often shortened to browser, is an application for accessing websites. When a user requests a web page from a particular website, the browser retrieves its files from a web server and then displays the page on the user's scr ...

, called WorldWideWeb, could both view and edit

web page A web page (or webpage) is a World Wide Web, Web document that is accessed in a web browser. A website typically consists of many web pages hyperlink, linked together under a common domain name. The term "web page" is therefore a metaphor of pap ...

s; but, as the Web grew, it became a read-only medium for most users. Whitehead and other like-minded people wanted to transcend that limitation. The meetings resulted in the formation of an IETF working group because the new effort would lead to extensions to HTTP, which the IETF had started to standardize. As work began on the protocol, it became clear that handling both distributed authoring and versioning together would involve too much work and that the tasks would have to be separated. The WebDAV group focused on distributed authoring, and left versioning for the future. (The Delta-V extension added versioning later see the Extensions section below.) The WebDAV

concluded its work in March 2007, after the Internet Engineering Steering Group (IESG) accepted an incremental update to . Other extensions left unfinished at that time, such as the BIND method, have been finished by their individual authors, independent of the formal working group.

Implementation

WebDAV extends the set of standard HTTP verbs and headers allowed for request methods. The added verbs include:

Properties

The properties of WebDAV protocol are name–value pair, in which a "name" is a Uniform Resource Identifier (URI) and the "values" are expressed through XML elements. Furthermore, the methods to handle the properties are PROPFIND and PROPPATCH.

Documents produced by the working group

The WebDAV working group produced several works: * a requirements document: "Requirements for a Distributed Authoring and Versioning Protocol for the World Wide Web" , issued February 1998 * a base protocol document (excluding versioning, despite its title): "HTTP Extensions for Web Distributed Authoring and Versioning (WebDAV)" , issued June 2007 (which updates and supersedes "HTTP Extensions for Distributed Authoring WebDAV" , issued February 1999) * the ordered collections protocol: "Web Distributed Authoring and Versioning (WebDAV) Ordered Collections Protocol" , issued December 2003 * the access control protocol: "Web Distributed Authoring and Versioning (WebDAV) Access Control Protocol" , issued May 2004 * a quota specification: "Quota and Size Properties for Distributed Authoring and Versioning (DAV) Collections" , issued February 2006 * a redirect specification: "Web Distributed Authoring and Versioning (WebDAV) Redirect Reference Resources" , issued March 2006

Extensions and derivatives

For versioning, the Delta-V protocol under the Web Versioning and Configuration Management working group adds resource revision tracking, published in . For searching and locating, the DAV Searching and Locating (DASL) working group never produced any official standard although there are a number of implementations of its last draft. Work continued as non-working-group activity. The WebDAV Search specification attempts to pick up where the working group left off, and was published as in November 2008. For calendaring, CalDAV is a protocol allowing calendar access via WebDAV. CalDAV models calendar events as HTTP resources in iCalendar format, and models calendars containing events as WebDAV collections. For groupware, GroupDAV is a variant of WebDAV which allows client/server groupware systems to store and fetch objects such as calendar items and address book entries instead of web pages. For MS Exchange interoperability, WebDAV can be used for reading/updating/deleting items in a mailbox or public folder. WebDAV for Exchange has been extended by Microsoft to accommodate working with messaging data. Exchange Server version 2000, 2003, and 2007 support WebDAV. However, WebDAV support has been discontinued in Exchange 2010 in favor of Exchange Web Services (EWS), a

SOAP Soap is a salt (chemistry), salt of a fatty acid (sometimes other carboxylic acids) used for cleaning and lubricating products as well as other applications. In a domestic setting, soaps, specifically "toilet soaps", are surfactants usually u ...

based

API An application programming interface (API) is a connection between computers or between computer programs. It is a type of software interface, offering a service to other pieces of software. A document or standard that describes how to build ...

Additional Windows-specific extensions

As part of the Windows Server Protocols (WSPP) documentation set, Microsoft published the following protocol documents detailing extensions to WebDAV: * S-WDVME Web Distributed Authoring and Versioning (WebDAV) Protocol: Microsoft Extensions. These extensions include a new verb and new headers, and properties that enable previously unmanageable file types and optimize protocol interactions for file system clients. These extensions introduce new functionality into WebDAV, optimize processing, and eliminate the need for special-case processing. * S-WDV Web Distributed Authoring and Versioning (WebDAV) Protocol: Client Extensions. The client extensions in this specification extend the WebDAV Protocol by introducing new headers that both enable the file types that are not currently manageable and optimize protocol interactions for file system clients. These extensions do not introduce new functionality into the WebDAV Protocol, but instead optimize processing and eliminate the need for special-case processing. * S-WDVSE Web Distributed Authoring and Versioning (WebDAV) Protocol: Server Extensions. The server extensions in this specification extend WebDAV by introducing new HTTP request and response headers that both enable the file types that are not currently manageable and optimize protocol interactions for file system clients. This specification also introduces a new WebDAV method that is used to send search queries to disparate search providers. * S-WEBDAVE Web Distributed Authoring and Versioning Error Extensions Protocol Specification. This SharePoint Front-End Protocol describes extended error codes and extended error handling mechanism specified in S-WDVto enable compliant servers to report error condition details on a server response.

WebDAV clients

WebDAV libraries

Alternatives to WebDAV

File Transfer Protocol The File Transfer Protocol (FTP) is a standard communication protocol used for the transfer of computer files from a server to a client on a computer network. FTP is built on a client–server model architecture using separate control and d ...

(FTP), a simple and widely adopted network protocol based on IP, allows users to transfer files between network hosts.

FTPS FTPS (also known as FTP-SSL and FTP Secure) is an extension to the commonly used File Transfer Protocol (FTP) that adds support for the Transport Layer Security (TLS) and, formerly, the Secure Sockets Layer (SSL, which is now prohibited by RFC756 ...

extends FTP for secure traffic. *

SSH File Transfer Protocol In computing, the SSH File Transfer Protocol, also known as Secure File Transfer Protocol (SFTP), is a network protocol that provides file access, file transfer, and file management over any reliable data stream. It was designed by the Inte ...

(SFTP), an extension of the Secure Shell protocol (SSH) version 2.0, provides secure file-transfer capability; and scp, a form of SFTP that runs as a single command similar to a regular cp (copy) command in the shell. * Rsync, a protocol and a command similar to scp, that can also skip rewriting identical files and portions of files, or skip newer files, etc. * A

distributed file system A clustered file system (CFS) is a file system which is shared by being simultaneously Mount (computing), mounted on multiple Server (computing), servers. There are several approaches to computer cluster, clustering, most of which do not emplo ...

such as the Server Message Block (SMB) protocol allows

Microsoft Windows Windows is a Product lining, product line of Proprietary software, proprietary graphical user interface, graphical operating systems developed and marketed by Microsoft. It is grouped into families and subfamilies that cater to particular sec ...

and open-source

Samba Samba () is a broad term for many of the rhythms that compose the better known Brazilian music genres that originated in the Afro-Brazilians, Afro Brazilian communities of Bahia in the late 19th century and early 20th century, It is a name or ...

clients to access and manage files and folders remotely on a suitable file server. Commonly used for multimedia streaming over

Ethernet Ethernet ( ) is a family of wired computer networking technologies commonly used in local area networks (LAN), metropolitan area networks (MAN) and wide area networks (WAN). It was commercially introduced in 1980 and first standardized in 198 ...

and widely supported by Smart TVs. * AtomPub, an HTTP-based protocol for creating and updating web resources, can be used for some of the use cases of WebDAV. It is based on standard HTTP verbs with standardized collection resources that behave somewhat like the WebDAV model of directories. * CMIS, a standard consisting of a set of Web services for sharing information among disparate content repositories, seeks to ensure interoperability for people and applications using multiple content repositories; it has both

- and AtomPub-based interfaces * Wiki software, such as

MediaWiki MediaWiki is free and open-source wiki software originally developed by Magnus Manske for use on Wikipedia on January 25, 2002, and further improved by Lee Daniel Crocker,mailarchive:wikipedia-l/2001-August/000382.html, Magnus Manske's announc ...

. * Linked Data Platform (LDP), a Linked Data specification defining a set of integration patterns for building RESTful HTTP services that are capable of read-write of RDF data. * Object storage such as OpenStack Swift or Amazon S3

References

* *

External links

Official WebDAV site

Awesome WebDAV
A curated list of awesome apps that support WebDAV and tools related to it.
Davfs2 project

Fusedav project

{{DEFAULTSORT:Webdav Internet protocols World Wide Web Consortium standards Working groups Hypertext Transfer Protocol Collaborative software Network file systems