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Last modified: January 03, 2006
WEBDAV (Extensions for Distributed Authoring and Versioning on the World Wide Web

"WebDAV is an Internet Engineering Task Force (IETF) working group that seeks to extend HTTP 1.1 for distributed authoring and versioning. It uses XML." The Working Group chairman is Jim Whitehead (University of California, Irvine). The Distributed Authoring and Versioning (WebDAV) standard was approved by the IETF in December, 1998.

What is WebDAV? "Briefly: WebDAV stands for 'Web-based Distributed Authoring and Versioning'. It is a set of extensions to the HTTP protocol which allows users to collaboratively edit and manage files on remote web servers."

The WebDAV working group "found that there was a pressing need to develop standard extensions to the HyperText Transfer Protocol (HTTP) for the following capabilities: 1) Metadata. The ability to create, remove, and query information about Web pages, such as its author, creation date, etc. Also, the ability to link pages of any media type to related pages. 2) Name space management. The ability to copy and move Web pages, and to receive a listing of pages at a particular hierarchy level (like a directory listing in a file system). 3) Overwrite prevention. The ability to keep more than one person from working on a document at the same time. This prevents the "lost update problem" in which modifications are lost as first one author, then another writes their changes without merging the other author's changes. 4) Version management. The ability to store important revisions of a document for later retrieval. Version management can also support collaboration by allowing two or more authors to work on the same document in parallel tracks." [from the Introduction]

"The DAV property model is based on name/value doubles. The name of a property identifies the property's syntax and semantics, and provides an address with which to refer to a property. The name and value of a property is expressed as a well-formed XML element, where the name of the property is the name of the XML element, and the value of the property MUST be either blank, or a well-formed XML element value."

"Unlike HTTP/1.1, WebDAV encodes method parameter information either in an Extensible Markup Language (XML) request entity body, or in an HTTP header. The use of XML to encode method parameters was motivated by the ability to add extra XML elements to existing structures, providing extensibility; and by XML's ability to encode information in ISO 10646 character sets, providing internationalization support. As a rule of thumb, parameters are encoded in XML entity bodies when they have unbounded length, or when they may be shown to a human user and hence require encoding in an ISO 10646 character set. Otherwise, parameters are encoded within HTTP headers. Section 9 describes the new HTTP headers used with WebDAV methods. In addition to encoding method parameters, XML is used in WebDAV to encode the responses from methods, providing the extensibility andinternationalization advantages of XML for method output, as well as input. XML elements used in this specification are defined in section 12." [draft-ietf-webdav-protocol-10, November 16, 1998]

Principal References

  • IETF WEBDAV Working Group - Home Page

  • IETF WEBDAV Working Group Charter

  • WebDAV Resources

  • WebDAV Specifications

  • [January 03, 2006] HTTP Extensions for Distributed Authoring - WebDAV. By Lisa Dusseault (Open Source Application Foundation). IETF WebDAV Working Group, Internet-Draft. Reference: 'draft-ietf-webdav-rfc2518bis-10'. Will obsolete RFC 2518 if approved. Date: December 30, 2005, expires July 3, 2006. "WebDAV consists of a set of methods, headers, and content-types ancillary to HTTP/1.1 for the management of resource properties, creation and management of resource collections, URL namespace manipulation, and resource locking (collision avoidance). RFC2518 was published in February 1999, and this specification makes minor revisions mostly due to interoperability experience... WebDAV uses XML for property names and some values, and also uses XML to marshal complicated request and response. This specification contains DTD and text definitions of all all properties (Section 14) and all other XML elements (Section 13) used in marshalling. WebDAV includes a few special rules on how to process XML (Section 16) appearing in WebDAV so that it truly is extensible..."

  • [December 31, 2003]   Proposed Calendar Server Extensions for WebDAV (CalDAV).    IETF has announced the publication of an initial working draft for Calendar Server Extensions for WebDAV (CalDAV). The CalDAV draft been submitted to the IETF CALSCH working group for consideration of the mechanisms designed to enable interoperable calendar access over WebDAV. The draft specification was commissioned at the Fall 2003 Minneapolis meeting of the IETF Calendaring and Scheduling Working Group Working Group and is intended as an exploration of the advantages of using WebDAV as well as a proposal for one way to model calendaring data, with some ideas for how to specify the features that go beyond WebDAV." Under the initial proposal, a CalDAV server would need to support WebDAV Level 1 and 2, WebDAV ACL, DASL (DAV Searching and Locating), and HTTP/SASL; WebDAV DeltaV support would be optional. The document describes certain features that are required for modern enterprise-level calendar systems are not present in HTTP or WebDAV, including fanout (server supports fanning out scheduling requests on behalf of the client), recurrance (support for recurring appointments are common in calendaring applications), and notifications (optimal way for the server to contact the client). "A CalDav repository, or server, is a calendaring-aware engine combined with a WebDAV repository. The CalDAV server or repository is the canonical location for calendar data, state information and semantics. The CalDAV server has significant responsibility to ensure that the data is consistent and compliant. Clients may submit requests to change data or download data. Clients may store the calendar offline and attempt to synchronize when reconnected, but changes to the repository occurring in between are not considered to be automatically disposable and clients should consider the repository to be the first authority on state. HTTP Etags and other tools help this work."

  • [June 05, 2003] "WebDAV Ordered Collections Protocol." By Jim Whitehead (UC Santa Cruz, Dept. of Computer Science) and Julian F. Reschke (greenbytes GmbH, editor); WWW. IETF WEBDAV Working Group, Internet-Draft. Reference: 'draft-ietf-webdav-ordering-protocol-08'. May 12, 2003, expires November 10, 2003. 43 pages. " This specification extends the WebDAV Distributed Authoring Protocol to support server-side ordering of collection members. Of particular interest are orderings that are not based on property values, and so cannot be achieved using a search protocol's ordering option and cannot be maintained automatically by the server. Protocol elements are defined to let clients specify the position in the ordering of each collection member, as well as the semantics governing the ordering. This specification builds on the collection infrastructure provided by the WebDAV Distributed Authoring Protocol, adding support for the server-side ordering of collection members. There are many scenarios where it is useful to impose an ordering on a collection at the server, such as expressing a recommended access order, or a revision history order. The members of a collection might represent the pages of a book, which need to be presented in order if they are to make sense. Or an instructor might create a collection of course readings, which she wants to be displayed in the order they are to be read. Orderings may be based on property values, but this is not always the case. The resources in the collection may not have properties that can be used to support the desired ordering. Orderings based on properties can be obtained using a search protocol's ordering option, but orderings not based on properties cannot. These orderings generally need to be maintained by a human user. The ordering protocol defined here focuses on support for such human-maintained orderings. Its protocol elements allow clients to specify the position of each collection member in the collection's ordering, as well as the semantics governing the ordering. The protocol is designed to allow support to be added in the future for orderings that are maintained automatically by the server..." Note: "The IESG has received a request from the WWW Distributed Authoring and Versioning Working Group to consider WebDAV Ordered Collections Protocol as a Proposed Standard. The IESG plans to make a decision in the next few weeks, and solicits final comments on this action. Please send any comments to the or mailing lists by 2003-6-19." [cache]

  • [April 10, 2003] "Technology Update: WebDAV Secures Collaboration." By Lisa Dusseault (Xythos Software; Co-Chair of the IETF WebDAV Working Group). In Network World (April 07, 2003). "Web-based Distributed Authoring and Versioning is an extension of HTTP that lets users collaborate via the Internet. The Internet Engineering Task Force approved it as a standards-track specification in 1998, and it has been deployed widely on multiple platforms and in applications from many vendors. WebDAV can be found in Web servers such as Apache and Microsoft Internet Information Server and now is also supported by leading document and content management vendors. WebDAV functionality also is embedded in common desktop operating systems, including Windows and Mac OS X, and popular applications from Adobe, Lotus, Microsoft and others... WebDAV access-control lists provide advanced control over read, write and sharing permissions for every file, further improving system security. Analysts recently have suggested that the file management features in WebDAV can make it a cost-effective alternative to traditional document management products. WebDAV imposes a common data model that includes collections, resources, locks and properties, and defines a common syntax using HTTP messages with custom methods, headers and bodies. Extending HTTP, WebDAV defines several methods for file management, such as Copy and Move, and Mkcol for creating new Web folders. The Lock and Unlock methods let a document be protected while the author makes changes. The Propfind and Proppatch methods let folders be browsed and offer flexible management of metadata. All these methods operate on HTTP resources, so any Web server that supports WebDAV provides an integrated system for secure authoring... So, where is WebDAV headed? It's quite possible that WebDAV will remain almost invisible to most users as it becomes part of everyday applications. The protocol is fulfilling its promise of extending current file systems beyond the LAN to include just about any user or resource on the Internet..."

  • [May 21, 2002] "Uniform Comparison of Data Models Using Containment Modeling." By E. James Whitehead, Jr. (Department of Computer Science, University of California, Santa Cruz, CA). Paper prepared for the ACM SIGWEB 2002 Hypertext Conference (ACM conference on Hypertext and Hypermedia), June 2002. "Containment data models are a subset of entity relationship models in which the allowed relationships are either a type of containment, storage, or inheritance. This paper describes containment relationships, and containment data models, applying them to model a broad range of monolithic, link server, and hyperbase systems, as well as the Dexter reference model, and the WWW with WebDAV extensions. A key quality of containment data models is their ability to model systems uniformly, allowing a broad range of systems to be compared consistently. ... Containment data modeling provides a modeling mechanism capable of uniformly representing the data models of a wide range of existing hypertext systems. Containment data modeling has been validated by presenting the models of 14 existing hypertext systems and reference models, the broadest survey to date of these models. The uniformity of containment modeling is highlighted by the ability to decompose and model both Dexter and the WWW in the same way as other systems, allowing them to be compared with each other and with other systems using a consistent model. The understanding of Dexter and the WWW that emerges from this process shows them to be non-distinguished peers with other hypertext systems, carrying their own design choices and tradeoffs, but otherwise with no special distinction to their data models. Containment data modeling provides a new technique useful in comparing hypertext system data models. By concisely representing system data models, and then grouping thems together, it is possible to quickly see similarities and differences among systems, including patterns for handling composites, anchors, and links. Since containment data modeling focuses on modeling the static aspects of system data models, it is complementary to architecture-focused models, such as Flag, and formal models of system semantics, such as the FOHM model, or Trellis' Petri-nets. While containment data models are a powerful and useful modeling technique, they alone do not give a complete picture of a hypertext system, and should be used in conjunction with other modeling techniques, providing multiple views of distinct aspects of each system. Containment data models show significant promise for modeling systems in other domains, such as Software Configuration Management and Document Management. In our future work, we look forward to extending this technique to these additional classes of systems, enabling us to perform substantive crossdomain comparison of information management systems..." See Emmet Whitehead's Curriculum Vitae for related papers on WebDAV and hypertext versioning. [cache]

  • [October 02, 2002] "WebWare Deals with Interwoven, Shows Fruits of WebDAV Support." By Patricia Evans. In The Seybold Report Volume 2, Number 12 (September 30, 2002). ISSN: 1533-9211. ['Interwoven will integrate WebWare's Mambo into its TeamSite package. Meanwhile, WebWare's WebDAV support is starting to pay off.'] "This month, WebWare announced an integration deal with content-management vendor Interwoven. It also debuted enhancements to its Mambo asset management system... According to WebWare, the integration will enable Interwoven clients to take advantage of features such as automatic asset versioning, tracking and routing of assets and will offer better support for video and audio assets... WebDAV support: it was at Seybold San Francisco last year that WebWare first declared support for WebDAV and for Adobe's newly announced XMP metadata-sharing platform. But Adobe applications (to say nothing of third-party products) that produced XMP proved to be a little farther down the development road. Not until early this year did Adobe release XMP- and WebDAV-capable versions of Illustrator, GoLive, InDesign and Photoshop. WebDAV-enabled software allows users to access the Mambo repository directly from the application. For example, a Photoshop user could retrieve an asset, edit it and return the updated version to the Mambo repository without leaving Photoshop. WebWare says it currently supports eight WebDAV-enabled applications." See: (1) "WEBDAV (Extensions for Distributed Authoring and Versioning on the World Wide Web"; (2) "Extensible Metadata Platform (XMP)."

  • [March 29, 2002] "Versioning Extensions to WebDAV. (Web Distributed Authoring and Versioning)." By Geoffrey Clemm (Rational Software), Jim Amsden (IBM), Tim Ellison (IBM), Christopher Kaler (Microsoft), and One Microsoft Way, Redmond, WA 90852 Jim Whitehead (UC Santa Cruz, Department of Computer Science). IETF Network Working Group. Request for Comments: 3253. March 2002. "This document specifies a set of methods, headers, and resource types that define the WebDAV (Web Distributed Authoring and Versioning) versioning extensions to the HTTP/1.1 protocol. WebDAV versioning will minimize the complexity of clients that are capable of interoperating with a variety of versioning repository managers, to facilitate widespread deployment of applications capable of utilizing the WebDAV Versioning services. WebDAV versioning includes automatic versioning for versioning-unaware clients, version history management, workspace management, baseline management, activity management, and URL namespace versioning... The benefits of versioning in the context of the worldwide web include: (1) A resource has an explicit history and a persistent identity across the various states it has had during the course of that history. It allows browsing through past and alternative versions of a resource. Frequently the modification and authorship history of a resource is critical information in itself. (2) Resource states (versions) are given stable names that can support externally stored links for annotation and link server support. Both annotation and link servers frequently need to store stable references to portions of resources that are not under their direct control. By providing stable states of resources, version control systems allow not only stable pointers into those resources, but also well defined methods to determine the relationships of those states of a resource... WebDAV Versioning defines both basic and advanced versioning functionality. Basic versioning allows users to: (1) Put a resource under version control (2) Determine whether a resource is under version control (3) Determine whether a resource update will automatically be captured (4) Create and access distinct versions of a resource. Advanced versioning provides additional functionality for parallel development and configuration management of sets of web resources... To maximize interoperability and the use of existing protocol functionality, versioning support is designed as extensions to the WebDAV protocol (RFC2518), which itself is an extension to the HTTP protocol (RFC2616). All method marshalling and postconditions defined by RFC 2518 and RFC 2616 continue to hold, to ensure that versioning unaware clients can interoperate successfully with versioning servers. Although the versioning extensions are designed to be orthogonal to most aspects of the WebDAV and HTTP protocols, a clarification to RFC 2518 is required for effective interoperable versioning... When an XML element type in the DAV: namespace is referenced in this document outside of the context of an XML fragment, the string DAV: will be prefixed to the element type. When a method is defined in this document, a list of preconditions and postconditions will be defined for that method. If the semantics of an existing method is being extended, a list of additional preconditions and postconditions will be defined. A precondition or postcondition is prefixed by a parenthesized XML element type that identifies that precondition or postcondition..."

  • HTTP Extensions for Distributed Authoring -- WEBDAV. RFC 2518, Standards Track, Proposed Standard. February, 1999. "This document specifies the WebDAV Distributed Authoring Protocol, a set of headers and methods which extend the Hypertext Transfer Protocol to provide capabilities for overwrite prevention (locking), properties, and namespace management."

  • (WEB)DAV Frequently Asked Questions

  • "A Brief Introduction to WEBDAV." September 18, 1998. [local archive copy]

  • [March 29, 2002] "WebDAV." By Rael Dornfest. Emerging Technology Brief from O'Reilly Research. March 26, 2002. "WebDAV (Web-based Distributed Authoring and Versioning, also called DAV) is a set of extensions to HTTP/1.1 (HyperText Transfer Protocol, the protocol spoken by Web browsers and servers) allowing you to edit documents on a remote Web server. DAV provides support for: (1) Editing: creating, updating, deleting (2) Properties: title, author, publication date, etc. (3) Collections: analogous to a file system's directory or desktop folder (4) Locking: prevents the confusion and data corruption caused by two or more people editing the same content at the same time WebDAV is platform independent, both in terms of client and server. This means that Macintosh, *nix, and Windows users can collaborate on Web content without all the usual conversion problems. Furthermore, it doesn't matter whether your documents are hosted on an Apache or Microsoft IIS server... WebDAV is an open standard, published by the IETF (the Internet Engineering Task Force) (RFC 2518). A completely open process, all it takes to join the WebDAV working group is subscription to and participation on a mailing list. Involved in the original development of WebDAV were representatives of companies the likes of Microsoft, Netscape, Novell, and Xerox. WebDAV support appears in a veritable cornucopia of Open Source projects, programming languages, commercial products, and services. WebDAV is baked right into the Windows (Web Folders) and Mac OS X operating systems as folders, that for all intents and purposes appear to be on your local machine, but are actually network connections to a remote server. The Zope Open Source content management system affords editing of content from well-known authoring tools like Adobe GoLive 5. DAV modules exist for most programming languages; they are either native or there are plug-ins for about every Web server in existence..."

  • Compare: DAV Searching and Locating (DASL)

  • Experimental XSLT stylesheet for conversion from RFC2629-conforming format to HTML. From Julian F. Reschke. [cache]

  • [October 16, 2001] "WebDAV Protocol Comes Of Age. Technology for collaboration via the Web arrives." By Cathleen Moore. In InfoWorld October 12, 2001. "Incubating in the standards process for several years, the WebDAV (Web-based Distributed Authoring and Versioning) protocol -- designed to add interoperability and collaborative capabilities to the Internet -- has been steadily making its way into the everyday tools of business users and stands poised to transform how users interact with the Internet. WebDAV is a set of extensions to the HTTP protocol that allows users to collaboratively edit and manage files on a remote Web server. Whereas the Internet historically has been limited to display and download capabilities, WebDAV embedded in software and systems promises to turn the Internet into a writable medium capable of supporting collaboration and distributed file sharing. The protocol, which is still being refined and tweaked through the Internet Engineering Task Force (IETF) standards process, has some features that include locking and unlocking capabilities to prevent the overwriting of changes, XML properties for the storage of metadata, and namespace manipulation capability copying and moving data. To ensure security, WebDAV adds SSL (Secure Sockets Layer) technology and wraps all transmissions in 128-bit encryption. Other important features that are being developed include version control and the ability to set access control lists. Among the many potential applications of WebDAV, secure Web-based file sharing holds the biggest promise for business users...for example, multiple remote workers using WebDAV-enabled systems and software can collaborate on shared documents wherever they are as long as they have Internet access. Other potential uses for WebDAV include editing contents of a document management system via the Web and virtual product development across distributed enterprises, according to observers. The protocol is just now at a stage of maturity, providing useful function in products that are currently hitting the market, [Bill] North says. A diverse array of vendors are embracing WebDAV across applications, software, servers, and OSes... Oracle currently supports WebDAV in iFS (Internet File System) and plans to add WebDAV functionality to Release 2 of its Oracle 9iAS Portal product, due by the end of the year... Microsoft for its part has built WebDAV support into its many products, including SharePoint Portal Server, Office XP, and Windows XP, which is due to be formally rolled out this month. WebDAV support integrated into Windows XP is notable because it enables any application running on top of it to be WebDAV-enabled as well... Other OSes from Apple and Novell are also taking advantage of WebDAV's collaborative functionality... Another vendor leveraging WebDAV is San Jose, Calif.-based Adobe Systems. The newest edition of Adobe Acrobat, Version 5.0, takes advantage of WebDAV to allow users to collaborate on and edit PDF documents via the Web. Using the WebDAV functionality embedded in Acrobat 5.0, a user viewing a PDF file can upload comments and edits to a shared data repository, which can be tapped by and added to by other workers connected to the Web server..."

  • [October 16, 2001] "Versioning Extensions to WebDAV." IETF Internet-Draft. Reference: 'draft-ietf-deltav-versioning-18'. September 11, 2001; Expires March 11, 2002. 106 pages. By Geoffrey Clemm (Rational Software), Jim Amsden (IBM), Tim Ellison (IBM), Chris Kaler (Microsoft), and Jim Whitehead (U.C. Santa Cruz). ['The IESG has approved the Internet-Draft 'Versioning Extensions to WebDAV' (draft-ietf-deltav-versioning-18.txt) as a Proposed Standard. This document is the product of the Web Versioning and Configuration Management Working Group. The IESG contact persons are Ned Freed and Patrik Faltstrom.'] Abstract: "This document specifies a set of methods, headers, and resource types that define the WebDAV Versioning extensions to the HTTP/1.1 protocol. WebDAV Versioning will minimize the complexity of clients that are capable of interoperating with a variety of versioning repository managers, to facilitate widespread deployment of applications capable of utilizing the WebDAV Versioning services. WebDAV Versioning includes: (1) Automatic versioning for versioning-unaware clients, (2) Version history management, (3) Workspace management, (4) Baseline management, (5) Activity management, and (6) URL namespace versioning." Namespace, etc: The DAV:href XML element is defined in RFC 2518, Section 12.3. Although WebDAV request and response bodies can be extended by arbitrary XML elements, which can be ignored by the message recipient, an XML element in the DAV namespace must not be used in the request or response body of a versioning method unless that XML element is explicitly defined in an IETF RFC... A 'precondition' of a method describes the state on the server that must be true for that method to be performed. A 'postcondition' of a method describes the state on the server that must be true after that method has completed. If a method precondition or postcondition for a request is not satisfied, the response status of the request must be either 403 (Forbidden) if the request should not be repeated because it will always fail, or 409 (Conflict) if it is expected that the user might be able to resolve the conflict and resubmit the request. In order to allow better client handling of 403 and 409 responses, a distinct XML element type is associated with each method precondition and postcondition of a request. When a particular precondition is not satisfied or a particular postcondition cannot be achieved, the appropriate XML element must be returned as the child of a top-level DAV:error element in the response body, unless otherwise negotiated by the request. In a 207 Multi-Status response, the DAV:error element would appear in the appropriate DAV:responsedescription element..." [cache]

  • [July 24, 2001] "WebDAV Access Control Protocol." IETF Internet Draft. Reference: 'draft-ietf-webdav-acl-06'. By Geoffrey Clemm (Rational Software), Anne Hopkins (Microsoft Corporation), Eric Sedlar (Oracle Corporation), and Jim Whitehead (U.C. Santa Cruz). June 21, 2001. Expires December 21, 2001. "This document specifies a set of methods, headers, and message bodies that define Access Control extensions to the WebDAV Distributed Authoring Protocol. This protocol permits a client to remotely read and modify access control lists that instruct a server whether to grant or deny operations upon a resource (such as HTTP method invocations) by a given principal." This specification is organized as follows. Section 1.1 defines key concepts used throughout the specification, and is followed by more in-depth discussion of principals (Section 2), and privileges (Section 3). Properties defined on principals are specified in Section 4, and access control properties for content resources are specified in Section 5. The semantics of access control lists are described in Section 6, including sections on ACE combination (Section 6.1), ACE ordering (Section 6.2), and principals required to be present in an ACE (Section 6.4). Client discovery of access control capability using OPTIONS is described in Section 7.1, and the access control setting method, ACL, is specified in Section 8. Internationalization considerations (Section 11) and security considerations (Section 12) round out the specification. An appendix (Section 19.1) provides an XML Document Type Definition (DTD) for the XML elements defined in the specification..." See the XML DTD... "The goal of the WebDAV access control extensions is to provide an interoperable mechanism for handling discretionary access control for content in WebDAV servers. WebDAV access control can be implemented on content repositories with security as simple as that of a UNIX file system, as well as more sophisticated models. The underlying principle of access control is that who you are determines how you can access a resource. The 'who you are' is defined by a 'principal' identifier; users, client software, servers, and groups of the previous have principal identifiers. The 'how' is determined by a single 'access control list' (ACL) associated with a resource. An ACL contains a set of 'access control entries' (ACEs), where each ACE specifies a principal and a set of privileges that are either granted or denied to that principal. When a principal submits an operation (such as an HTTP or WebDAV method) to a resource for execution, the server evaluates the ACEs in the ACL to determine if the principal has permission for that operation." See the news item. [cache]

  • [January 23, 2001] See also: Versioning Extensions to WebDAV, which is intended to be moved into the standards track as a "Proposed Standard." The last call comment period ends February 1, 2001. Reference: IETF Internet-Draft 'draft-ietf-deltav-versioning-12'. January 20, 2001. 95 pages. By Geoffrey Clemm (Rational Software), Jim Amsden (IBM), Chris Kaler (Microsoft), and Jim Whitehead (U.C.Irvine). The resource properties defined in the versioning extensions to WebDAV are expressed in XML notation. Document abstract: "This document specifies a set of methods, headers, and resource types that define the WebDAV Versioning extensions to the HTTP/1.1 protocol. WebDAV Versioning will minimize the complexity of clients that are capable of interoperating with a variety of versioning repository managers, to facilitate widespread deployment of applications capable of utilizing the WebDAV Versioning services. WebDAV Versioning includes: (1) version history management, (2) automatic versioning for versioning-unaware clients, (3) workspace management, (4) baseline management, (5) activity management, (6) variant management, and (7) URL namespace versioning."

  • [September 21, 2001] "PDF Collaboration In Action. [Acrobat-Based Collaboration: How Well Does It Work? Workflow.]" By Bernd Zipper and John Parsons. In Seybold Report: Analyzing Publishing Technology [ISSN: 1533-9211] Volume 1, Number 11 (September 03, 2001), pages 7-12. ['Paper-based approval processes are generally at odds with shrinking deadlines, multi-departmental reviews and the needs of cross-media production. While numerous vendors have developed network-savvy methods for viewing, annotating and approving electronic files, many of those systems are proprietary in nature and few fully support PDF. One of Acrobat 5's significant new features is the ability to add comments and digital signatures online, forming the basis of a PDF-based collaborative workflow. We tested the new features and examined their strengths and weaknesses.'] "One of the significant new features of Acrobat 5, released in April, was the ability to add comments and digital signatures online. Although Adobe's tools are rudimentary, they form the basis of a collaborative workflow that is based, not on a proprietary raster file, but on PDF, which is widely recognized as an open, flexible and data-intensive format. The basic workflow. Acrobat 5's online workflow means that a PDF can be uploaded to a Web server, viewed in a browser by any prospective collaborator, and annotated online. Multiple users may view online PDFs, but must upload and download comments as a separate step... A separate server is required to hold the FDF files created by this commenting process. Adobe provides two methods for doing this: designating a shared folder on a network server, or specifying the URL of a WebDAV server... Importing and exporting annotations (FDF files) is handled via the Comments pane, or from the File menu... Adobe developed FDF as a 'transport format' for flexible transfer of information. For example, it is used for transferring the contents of tables or fields. The FDF format is based on the syntax of PDF. Its descriptions of objects and data are similar to those used by PDF itself, and they offer many options for display. Using this transport format, it is possible to forward and exchange data collected from forms, notes and annotations, and even optical markings... With Acrobat, there are two possible solutions for uploading PDF files to a Web server. One is WebDAV, which is an extension of the HTTP 1.1 protocol... WebDAV (Web Distributed Authoring and Versioning) extends HTTP to add the capability of securing data on the server; members of a team can use WebDAV to work on the same document at the same time, without being in the same place. The shared access is implemented by functions such as file locking and version control. The locking feature allows a user to temporarily block access to a file while he or she is working with it. Once the changes are completed, it is unlocked again. Locking and unlocking happen automatically, controlled by WebDAV, to avoid a 'collision.' It is not necessary to maintain a network connection during the time the lock (called a 'persistent lock') is applied to a file. Thus, a file can be opened online and edited offline. Subsequently, the changes are 'written' to the server. WebDAV also provides for the association of properties with documents. These properties are metadata encoded as XML. WebDAV distinguishes between 'dead' and 'live' properties. Live properties are generated by the server itself, including such things as creation date and date of modification. Dead properties are name-value combinations that incorporate a URL and XML coding. In the case of Acrobat, these are online annotations... The full $249 version of Acrobat 5 is required for users to view online comments, even if the user does not need to make comments. Neither the free Reader nor the recently introduced Approval product ($39) can view WebDAV-hosted online comments... Acrobat's online capabilities have increased the potential for collaborative workflow, using a common file format and (at least for comments) the obvious strengths and popularity of WebDAV. As tantalizing as this potential is, however, we feel the process is unfinished, and that practical solutions are still to come..."

  • [March 15, 2001]   W3C Releases Jigsaw 2.2.0 Web Server Platform with WebDAV Support.    Jigsaw is W3C's open source "leading-edge Web server platform which provides a sample HTTP 1.1 implementation and a variety of other features on top of an advanced architecture implemented in Java. The server uses an object-oriented approach when it comes to the storage of files and the processing of incoming requests, making it both more efficient and easily extensible." JigXML (the Jigsaw XML format) is used by Jigsaw to store the resources metadata. The version 2.2.0 release of Jigsaw includes enhanced support for WebDAV, and a parser for dates in ISO 8601 format. An updated online tutorial documents how to configure Jigsaw as a WebDAV server, and a package with a specific WebDAV configuration will follow shortly. WebDAV ('Web-based Distributed Authoring and Versioning') "is a set of extensions to the HTTP protocol which allows users to collaboratively edit and manage files on remote web servers." Other features in 2.2.0 are Servlet 2.2 implementation; new RFC 2616 compliant Cache; image metadata extraction using Content Negotiation; and Digest Authentication and ACL based authentication. [Full context]

  • [November 28, 2000] Jigsaw supports WebDAV. The W3C's Jigsaw development team recently released a downloadable version of the Jigsaw Web server platform with a WebDAV package. Jigsaw is a W3C Open Source Project which provides a sample HTTP 1.1 implementation and a variety of other features on top of an advanced architecture implemented in Java. The new WebDAV implementation is "based on Jigsaw 2.1.2, and has been tested with cadaver, DAVExplorer and WebFolders." WebDAV (Web-based Distributed Authoring and Versioning) is an XML based protocol which "defines a set of new methods (PROPFIND, PROPPATCH, MKCOL, COPY, MOVE, LOCK, UNLOCK) and a set of new headers (DAV, Depth, If, Destination, ...); it supplies a set of extensions to the HTTP protocol which allows users to collaboratively edit and manage files on remote web servers." For additional references, see: (1) the WebDAV FAQ document; (2) the article by Tom Bednarz showing how to enable WebDAV (mod_dav) for the Apache server that ships with Mac OSX (beta).

  • [June 13, 2000] "Apache Now Supporting Open-Source WebDAV module and the Writable Web." " (Web-based Distributed Authoring and Versioning) and the Apache Software Foundation (ASF) today introduced an add-on to the Apache HTTP Server that will provide its 9 million users unprecedented control of information on the Web. With the release of the mod_dav module, authored by one of the ASF's volunteer contributors, the world's number one Web server gains new power. mod_dav adds WebDAV capabilities to the Apache HTTP Server, an open-source software product. With this addition, the ASF ensures its users will have the most secure, efficient, and extensible server available..."

  • [March 16, 2000] "Communicating XML Data Over the Web with WebDAV." By Craig Neable and Sean Lyndersay. From MSDN Web Workshop. (March 03, 2000). ['Learn about WebDAV, which has become an important communication protocol for the Web as an extension to HTTP 1.1, and how it could be useful in your client/server architecture.'] "With increased focus on Internet standards and network interoperability, WebDAV (Web Distributed Authoring and Versioning) has become an important communication protocol for the Web as an extension to HTTP 1.1 (see IETF RFC 2616 for more information). The WebDAV specification (see IETF RFC 2518 for more information) was published by the Internet Engineering Task Force (IETF) in February 1999, with significant contributions from Microsoft, and with support from many third-party vendors such as Netscape, Xerox, IBM, and Novell. At Microsoft, WebDAV has found application in many different areas. It enables rich, collaborative publishing to Microsoft Internet Information Services (IIS) 5.0 servers via the Web. It is the protocol behind the Microsoft Office 2000 Web Folders. And it is the technology that provides a Web interface to the Microsoft Exchange 2000 Web Store, allowing direct access to Exchange's object-oriented, hierarchical database over the Web. Because of its inherent integration with Extensible Markup Language (XML), WebDAV not only has a large dependency on XML, but also has emerged as an excellent method for communicating XML data over the Web. However, before the strength of coupling these technologies can fully be understood, it is important to understand what WebDAV is and how it could be useful in your client/server architecture..." See also the WebDAV Web site.

  • [November 22, 2000] "Talks: A Uniform Interface for Authoring." By Edd Dumbill. From November 13, 2000. ['In the first session of the XML DevCon Fall 2000 conference, Greg Stein delivered an introduction to WebDAV, Web Distributed Authoring and Versioning protocol.'] "In the first session of the XML DevCon Fall 2000 conference, Greg Stein delivered an introduction to WebDAV, the Web Distributed Authoring and Versioning protocol. Stein is an open source developer working with WebDAV and Python -- he is the author of the mod_dav Apache DAV support, soon to be an integral part of Apache 2.0. WebDAV is an open protocol, standardized through the IETF, which uses XML and HTTP 1.1 to provide an interoperable layer for distributed web authoring. Essentially, it provides a uniform layer over filesystems, data repositories, etc. that supports more or less filesystem-like semantics: collections (like directories), resources (like files), properties (resource metadata), and locking... The benefits of this technology, according to Stein, are available for all concerned in the authoring process: (1) The reader of a document gets the ability to retrieve metadata about a document, and to retrieve this information from client tools. (2) The author of a document gets a standard way to place content on a server, and can use any authoring tools that support WebDAV. They also get the ability to tag documents with metadata and employ locking to ensure documents aren't overwritten by others while they're being worked on. (3) The administrator of a server gets a lot of flexibility from running DAV. The URL-space of the server doesn't have to match up with the filesystem, avoiding ugly dependencies on physical media, and authorization is performed by HTTP authentication, meaning users who want to place content on the server don't need to have system accounts, with the concomitant security risks. Because it's based on top of HTTP 1.1, WebDAV reaps all the pre-existent advantages of HTTP, such as through-firewall operation, security, and authentication features. By adding new verbs to HTTP like PROPFIND, PROPPATCH, etc., WebDAV provides facilities for metadata and locking..."

  • The Jakarta Slide project - The goal of this project is to provide an open-source and standards-based contant management framework. Slide is a Content Management and Integration System, which can be seen as a low-level content management framework. Conceptually, it provides a hierarchical organization of binary content which can be stored into arbitrary, heterogenous, distributed data stores. In addition, Slide integrates security, locking, content versioning, as well as many other services. It can integrate and manage data stored within external repositories, requiring only small abstraction layers to be written for each repository. That way, Slide can integrate the data from various physical locations in a hierachical and unified way. Slide uses can range from managing intranet application content (such as the portal) to using it as a file server. Slide also offers a WebDAV access module (implemented as a servlet). WebDAV is an IETF standard endorsed by companies like Microsoft, IBM, Novell, Adobe and many others. It makes Slide an ideal choice for web-based content management. All the data managed by Slide can be accessed through WebDAV, and enable remote administration and manipulation of the data managed by Slide using standard third party tools, along with the custom ones provided in the Slide distribution as additional tools...:

  • Proposed Extensions to WebDAV Properties. By James Amsden (IBM). Reference: "draft-ietf-webdav-properties-extension-00.txt" Abstract: "The WebDAV protocol defines facilities for adding properties to Web resources. These properties consist of name/value pairs interchanged using XML. The protocol includes the PROPFIND method for accessing properties, and the PROPPATCH method for updating and removing properties. Experience building both WebDAV clients and a WebDAV server indicates the need for three minor extensions to the current properties protocol: 1) allow PROPPATCH to create and initialize the properties of a resource that did not exist, 2) distinguish between adding a new property, and setting the value of an existing property of a resource, and 3) give client applications more control in specifying how PROPPATCH errors should be handled." [cache]

  • [May 10, 1999] "WebDAV: Evolving the Web into a Read and Write Medium." [MSDN Interview with] Jim Whitehead, the Chair of the WebDAV Working Group. April 07, 1999. "WebDAV is dependent on the XML, and XML namespaces standards. WebDAV uses XML to send information across the wire, and also uses XML as the format for property values. XML provides two major benefits to WebDAV, extensibility and internationalization. Since extra tags can be introduced anywhere in a stream of XML, we can extend the protocol, or extend our properties easily. Since XML supports multiple character sets, we can record property values which are readable by people from many different countries. Since WebDAV extends HTTP, we're also dependent on HTTP, and also the URL standard. HTTP gives WebDAV a lot of leverage, since we can use standards which work with HTTP, like the Digest authentication standard.

  • [July 13, 1999] "Intraspect Delivers Industry Leading Support for Microsoft Office 2000. Industry's First WebDAV-Compliant Collaborative Knowledge Management Solution." - "Intraspect Software, the market leader in Collaborative Knowledge Management applications, announces full support for Microsoft Office 2000 and the WebDAV protocol in their flagship product, Intraspect Knowledge Server (IKS). Using Intraspect, Microsoft Office 2000 users are 'one-click-away' from building secure, collaborative knowledge portals, to stay better connected and make better, faster decisions over the web. . . 'I am very excited that Intraspect is adding WebDAV support to its Intraspect Knowledge Server,' said Jim Whitehead, chair of the Internet Engineering Task Force (IETF) WebDAV working group. 'WebDAV support is a natural for web-based collaboration since it provides a standard, non-proprietary way to collaboratively author documents, web pages, images, and XML. By adding their weight to the WebDAV standard, Intraspect brings us closer to achieving the original vision of the Web as a writeable, collaborative medium'. WebDAV has considerable backing from Microsoft, Netscape, and other industry leaders in standards-based Internet computing. Microsoft's Internet Explorer 5.0 and all Microsoft Office 2000 applications are WebDAV clients. The WebDAV specification is available at Further information on WebDAV can be found at the WebDAV resources site at"

  • [October 06, 2000] "Use of a Semantics Register with WebDAV Properties." By Eliot Christian (U.S. Geological Survey, 802 National Center, Reston, VA 20192). WEBDAV Working Group, Internet Draft. Reference: 'christian-prop-semantics-00.txt', April 24, 2000. This document specifies a mechanism to associate a WebDAV (WEBDAV) property with an entry in a Semantics Register. A Semantics Register documents the meaning of properties in a formal manner and may be implemented with schema technologies such as Extensible Markup Language (XML) Schema or Resource Description Framework (RDF) Schema . Schema technologies expose the derivation of complex properties from simpler concepts, as demonstrated in the Basic Semantics Register for data elements used in Electronic Data Interchange. Registering the meanings of properties in this manner can enhance interoperability across systems and throughout the long-term information life cycle." Background: "It is often important to associate with a property some assertions in addition to its name and contents: assertions such as alternate labels or the property's semantic or syntactic relationship to other properties in the same or other systems. In organizing these assertions, a Semantics Register serves as an important tool for documenting a system and enabling interoperability among systems. When implemented with schema technologies, a Semantics Register can expose how complex properties are derived from simpler concepts. This use is demonstrated in the Basic Semantics Register (BSR), wherein thousands of complex data elements used in Electronic Data Interchange are constructed from commonly understood concepts. A Semantics Register can be referenced within WebDAV through the XML Namespace attribute. For example, assume there is a Semantics Register for Open Document Management (ODMA) properties at the URI '', and one of the ODM properties has an attribute ID 'ODM_CHECKEDOUTBY'. This hypothetical Semantics Register can be referenced in the value of an 'xmlns' attribute on the 'prop' element of a WebDAV 'propfind'..." [cache]

  • [October 06, 2000] "WevDav, IIS, and ISAPI Filters." [INTERNET PROGRAMMING.] By Martin Hallerdal. In Dr. Dobbs Journal (November 2000), pages 114-119. "The web-based Distributed Authoring and Versioning (WebDAV) specification defines a set of extensions to the HTTP protocol that let you collaboratively edit and manage files on remote web servers. Additional resources include webdav.txt (listings) and (source code)."

  • [May 10, 1999] "First WebDAV Products See the Light of Day." By Jeff Walsh and Bob Trott. In InfoWorld Volume 21, Issue 18 (May 03, 1999), page 8. "Proprietary methods for Web developers to interact with Web servers are becoming unnecessary, because products are now beginning to ship which support the Web Distributed Authoring and Versioning (WebDAV) Protocol. WebDAV is a proposed standard of the Internet Engineering Task Force, and provides Web servers with the equivalent of a network file system for exchanging data via HTTP. Glyphica and Microsoft are both delivering WebDAV support in the current beta versions of their server products, and Zope, an open-source Web application development environment, also added WebDAV functionality last week." See "Glyphica Launches New WebDAV Server."

  • [August 17, 2000] Content Management Solution Kit (Athens). From ICL. "Athens offers a complete solution for stand-alone publishing sites, comprising functions like content storage, administration, interchange, and publishing. Alternatively, Athens may be combined with other solution kits and external components through its many integration facilities: at its heart is the industry standard WebDAV protocol with corresponding API, and virtually all the components of Athens can be substituted." See the full article.

  • WWW Distributed Authoring and Versioning Charter; [local archive copy]

  • Preliminary WebDAV XML Elements DTD

  • mod_dav: a DAV module for Apache

  • From Fabio Vitali (Seminario WebDAV a Bologna, 1999-03-01): webdav_flyer.pdf WebDAV.pdf

  • DAV Resources [Greg Stein]

  • HTTP Extensions for Distributed Authoring -- WEBDAV Reference: draft-ietf-webdav-protocol-09, October 22, 1998. [local archive copy]

  • Internet Draft - WEBDAV [draft-ietf-webdav-protocol-03] September 29, 1997. [archive copy]

  • "Requirements for a Distributed Authoring and Versioning Protocol for the World Wide Web." Network Working Group, Request for Comments: 2291. February 1998. By: J. Slein (Xerox Corporation), F. Vitali (University of Bologna), E. Whitehead (U.C. Irvine), and D. Durand (Boston University). [local archive copy]

  • "WebDAV to Ease Web Authoring. Protocol to aid collaborative development is under review." By Brian Hannon. In PC Week Volume 15, Number 25 (June 22, 1998), page 8.

  • [December 17, 1998] "New Internet Standard Approved to Streamline Process for Editing Documents on Web. UC Irvine Researchers Say 'Distributed Authoring' Standard Will Help Internet Fulfill its Potential as a True Collaborative Resource." - "... the new Distributed Authoring and Versioning (WebDAV) standard will make it possible for web users in distant locations, whether separated by two houses or two continents, to write, edit and save shared documents without scuttling each other's work, regardless of which software program or Internet service they are using."

  • [October 07, 1998] Press release: "Microsoft Outlines Broad Product Support for WebDAV. Microsoft Continues to Embrace Open Standards by Supporting HTTP Extensions That Will Enable the Reading and Writing of Web Documents." - "at Fall Internet World 98, Microsoft Corp. emphasized its commitment to customer-focused open standards by outlining its plans to use WebDAV in a variety of future products. WebDAV, or Web Distributed Authoring and Versioning, is a set of extensions to HTTP 1.1 that will enable people to read and write documents over the Web."

  • [October 27, 1998] "Microsoft Supports WebDAV." By Richard Karpinski. In InternetWeek Issue 737 (October 19, 1998), page 33. "Microsoft said it will incorporate WebDAV support into Windows NT 5.0, Office 2000 productivity applications, FrontPage 2000 Web authoring tools and BackOffice services. Web Distributed Authoring and Versioning (WebDAV) is a set of extensions to HTTP 1.1 that establishes an interactive mechanism for reading, writing and updating documents over the Web. Its goal is to provide a standard way for Web tools to handle Web workflow and document publishing."

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