- Jim Whitehead
- Full day
- To be announced
- Presenter Bio
Jim Whitehead is the Chair and Founder of the Internet
Engineering Task Force (IETF) working group on Web
Distributed Authoring and Versioning (WebDAV), and is a
co-author on all major specifications produced by this
working group. Jim additionally spearheaded the formation of
the DeltaV working group for Web versioning and
configuration management, and is an author on the DeltaV
protocol specification. Jim has led several student teams
developing prototype WebDAV implementations, including the
WebDAV Explorer client.
Jim is also an Assistant Professor of Computer Science at
the University of California, Santa Cruz. His research
interests include hypertext versioning, collaborative
authoring, web protocols, open hypermedia (the Chimera
system), configuration management, and software
architecture. Jim has a Ph.D and MS in Information and
Computer Science from U.C. Irvine (Ph.D. dissertation: "An
Analysis of the Hypertext Versioning Domain"), and a BS in
Electrical Engineering from the Rensselaer Polytechnic
At present, the Web is primarily a read-only medium,
providing excellent support for browsing content, and
limited support for authoring new content. WebDAV is a
standard developed by the Internet Engineering Task Force
(IETF) for extending the Web with collaborative authoring
capability, and is supported by such industry-leading
tools as Office 2000, Photoshop 6, GoLive 5, Internet
Explorer 5, Mac OS X, Apache, Internet Information
Services 5, Oracle iFS, and Jigsaw, along with Web storage
sites such as Driveway, My Docs Online, and
Sharemation. Building on this strong base of support, the
DeltaV protocol adds versioning and configuration
management capabilities to WebDAV servers. With DeltaV, it
is possible to record the revision history of Web
resources, work on collections of resources in isolation
from other collaborators (workspaces), and create
consistent configurations of these resources.
This tutorial gives an overview of the WebDAV Distributed
Authoring protocol (RFC 2518), and the Web Versioning and
Configuration Management protocol (DeltaV). This is a
novice-to-intermediate level tutorial, which assumes some
knowledge about the hypertext transfer protocol (HTTP),
although a brief overview of this protocol will be given
during the course.
The WebDAV Distributed Authoring protocol provides
- Overwrite Prevention: Locking facilities allow a
document author to prevent modifications by other authors
during an edit session, thus preventing the "lost update"
- Properties: WebDAV properties are name, value pairs
which can be used to record metadata about a web
resource, such as it's author, creation date, length,
etc. WebDAV properties are well-formed Extensible Markup
Language (XML), and hence can support Resource
Description Framework (RDF) values.
- Collections: The ability to create sets of related
documents and to retrieve a hierarchical membership
listing (like a directory listing in a file
- Namespace Operations: The ability to copy and move
single web resources, and to copy, move and lock entire
hierarchies of web resources.
The Web Versioning and Configuration Management protocol
(DeltaV) adds capabilities for:
- Versioning: Recording the revision history of a
document over time. Versioning can be explicit, using
checkin/checkout, or automatic, with WebDAV locks
controlling creation of revisions.
- Workspaces: Working on a group of documents in
isolation from all other active collaborators.
- Baselines: Recording a consistent configuration of
resources at a particular instant in time. This is
useful for recording the released state of a collection
of source code, or documents.
- Activities: Calling a group of revisions a logical
change. For example, fixing an error in source code
might involve making several revisions.
By using these operations, both existing HTML authoring
applications, as well as more traditional word processing,
spreadsheet, and image manipulation applications can
support remote collaborative authoring and
versioning. Since a WebDAV-enabled application can save
directly to the web, and makes use of the overwrite
prevention capabilities, these applications provide a way
to seamlessly move from individual to collaborative
work. So, using a WebDAV-enabled word processor, you can
begin work on a document, then later realize you need to
add several co-authors. After saving your document to the
web, and emailing the URL to your collaborators, you can
all begin to collaboratively work on the document in-place
on the web.
Building upon its current strong base of supporting
tools, in the next 1-2 years WebDAV is expected to be
broadly adopted by content authoring tools. This will
bring the benefits of the writeable Web to millions of
users, opening significant opportunities for Internet
Service Providers, Web storage sites, document management,
content authoring tools, protocol developers, and
researchers. Furthermore, Web write-enabling existing
applications is just the first phase of WebDAV adoption.
DeltaV will allow the Web to be used as the core
infrastructure for remote software development, especially
Open Source, replacing the remote CVS protocol. With its
automatic versioning capabilities, DeltaV also allows
existing WebDAV authoring tools to take advantage of
WebDAV/DeltaV is one of the most substantial, yet
under-hyped changes to the core architecture of the Web.
By attending this tutorial, you will develop a deep
understanding of the capabilities and potential of this
increasingly important standard.