> OHS

Open Hyperdocument System (OHS)    (01)

I worked with Doug Engelbart on his Open Hyperdocument System from 2000-2002. In the process, I learned an enormous amount, and my experiences working with Doug strongly influenced the creation of Blue Oxen Associates. These pages document the work that I and others did on the OHS.    (02)

I created the OHS Launch Community on June 14, 2001, an ad-hoc group with a six month deadline, whose goals were to achieve a common understanding of the OHS, to document this collective knowledge, and to facilitate collaboration among our members. We completed our discussions on November 9, 2001.    (035)

If you are new to the project, and are looking for some background information, you should examine my recommended readings.    (03)

Discourse    (04)

The majority of past discourse on this project occurred over face-to-face discussions and on two open mailing lists: unrev-ii and ohs-dev. The former was originally established for Doug's Winter 2000 Colloquium at Stanford; the latter was for technical discussion. Additionally, the OHS Launch Community discussed many pertinent issues on its ohs-lc mailing list.    (05)

Early on, we experimented with a Wiki, with varying levels of success. That Wiki is no longer available.    (06)

From May to October 2000, several face-to-face meetings were held at SRI. Agendas and minutes for most of these meetings are available.    (07)

Technical Whitepapers    (08)

Title Last Updated First Published
Case Study: Adding Purple Numbers to Web Sites May 27, 2001 May 27, 2001
An Unofficial Introduction to Groves April 5, 2001 April 5, 2001
An Introduction to Purple May 1, 2001 January 31, 2001
OHS Requirements February 8, 2001 January 31, 2001
OHS Scenarios February 8, 2001 January 31, 2001
OHS Use Cases February 8, 2001 January 31, 2001

Conceptual Whitepapers    (09)

Title Last Updated First Published
A Strategy for Evolving the OHS February 8, 2001 February 8, 2001
What Is the Open Hyperdocument System? January 31, 2001 January 31, 2001

My Attic    (010)

An XML DTD for E-mail    (011)
One of our first target file formats was e-mail. I developed and released a simple DTD for RFC822 documents on August 2, 2000, and hacked a Perl script that transformed e-mail into this XML vocabulary. I also drew an architecture diagram that demonstrated how these tools could be integrated into existing e-mail archival/list server programs. (The xfig document used to generate this diagram is also available.) This work should be deprecated in favor of the XML Mime Transformation Protocol. I'm currently applying some of these and other ideas to the design of a peer-to-peer mail archive repository.    (012)
The Open Hyperdocument System: An Open System for Collaborative Knowledge Work    (013)
This is a proposal I drafted, with help from Lee Iverson and Pat Lincoln, and submitted to NASA Ames on July 13, 2000. The proposal was not accepted. Since we submitted this proposal, our thinking regarding this project has evolved immensely. Nevertheless, several of the fundamental elements in this proposal remain true today, and it is worth culling for background information.    (014)
Proposing the BSD License for the Open Hyperdocument System    (015)
One of the first subjects we tackled when we began meeting in the spring of 2000 was what open source license to use. I proposed adopting the BSD license, and posted this paper on June 27, 2000 to explain why. Later that summer, we agreed to use the Apache license for the project. However, I suspect that this decision will be reevaluated once the project gets closer to developing some real code.    (016)
Summarizing the OHS    (017)
One of our most challenging tasks has been to explain what exactly the OHS is. This document compiled some of the attempts by members of our community, and was published on June 1, 2000.    (018)

Tools    (021)

perlIBIS    (037)
perlIBIS is a set of Perl modules for representing, manipulating, and converting IBIS dialog maps.    (038)
Purple    (022)
Purple is a small suite of tools for generating purple numbers on an HTML web page (such as the numbers on this page). It consists of an XML DTD and scripts written in Perl and XSLT. These purple HTML numbers was invented by Doug as a way to bootstrap some of the granular addressability capabilities of his Augment system onto the World Wide Web.    (023)
a2h    (024)
I wrote a tool to generate HTML files from Augment data files, based on some work originally done by Shinya Yamada. Raylene Pak, who worked on the Augment system in the 1980s, is developing a backend for Augment that will export data files more easily. Her work, in conjunction with this tool, will allow Doug to dump 30 years of content currently stored on the Augment system (including annotated source code for Augment itself!) onto the Web, so that the rest of us can benefit from it.    (025)

Nicholas Carroll has posted some documentation for the Augment Smalltalk client.    (027)

A Note on the Name    (028)

Doug coined the term "Open Hyperdocument System" in 1985. Since then, many others have borrowed the acronym "OHS" for similar purposes, some independently and some after learning of Doug's work.    (029)

The most well known is the Open Hypermedia System Working Group, which was launched in 1994. The community is active, and has produced much useful work, some of which is referenced in various W3C reports and standards. Our efforts are currently independent of the OHSWG, although perhaps this will change at some point. We have much to learn from the work done by others in this area.    (030)

Because of the somewhat widespread use of the term, I think that we may be better off adopting a different name, despite the fact that Doug invented the term in the first place. There is precedence for this in many communities; for instance, the Foresight Institute is constantly evolving and marketing new terminology in the field of nanotechnology, as existing terms get hijacked by others. I recently suggested that we rename the OHS to OHE, for "Open Hyperdocument Environment" to emphasize the broad scope of this project. Doug is not entirely opposed to this proposal, and it may eventually happen.    (031)

Acknowledgements    (032)

I have benefitted from valuable discussions with many, many people, too numerous to mention. However, I am especially indebted to Eric Armstrong, Lee Iverson, Jack Park, and most importantly, Doug Engelbart, all of whom, from my first involvement with this project, took time out of their busy schedules to share and explain their ideas and comment on my own.    (033)

Much of our work has been supported indirectly by people who have graciously volunteered a variety of resources to our cause. In this regard, special thanks go to Patrick Lincoln at SRI and Christine Peterson at the Foresight Institute.    (034)