Etech a Sketch, Part 2

by Daniel Smith

Tim O'Reilly - O'Reilly Radar

"The future is here. It's just not evenly distributed yet"

-- William Gibson

Tim talked about some of the Driving Ideas that guide
O'Reilly. A big theme is: knowing what's cool, and evangelizing it.

Recognize Alpha Geeks, and leverage their expertise:

  • pay attention to what they are doing

  • recognize who is being looked up to

On the editorial side, O'Reilly looks for disruptive
technologies. Disruptive Tech tends to be bottom-up,
where some grassroots development takes over the scene.
The Mosaic web browser would be one example. It didn't
come from some big company. It came from college students.

Tim's view is that Open Source is all about Wide Area
Networking. For more on this particular talk, see href="">David
Weinberger's post

Jo Walsh - Gonzo Collaborative Mapping on the Semantic Web

Jo is working on a collaborative mapping
of points in London.
A couple of interfaces to it are via Jabber (
or AIM (mudlondon) You can
navigate around London via roads and the Tube. Some well-known (and not
so well known) places (such as the Victoria and Albert Museum) can
be navigated to. Try "go Picadilly Circus". With a little exploration,
you will find links to web sites of nearby shops

The slides to this talk are available in a href="">gzip'ed file from If my reading of Jo's material is correct, the REST
interface to the RDF map of spaces, and connections between them,
could act as a back end to a visual web (or otherwise net-connected
interface), allowing many users to navigate, annotate existing
locations, add new ones, and jump to web sites that have been
associated with them.

When you consider the work being done by Jo, by,
by Joshua of, and by a multitude of other projects,
the mind starts to boggle. The space of relating the physical
world into the web has a lot of angles and applications. I think
the dimension of time is going to be a necessary component
for many of them. The reasoning will be that for any popular
physical space, you will need a method of filtering out points
in order to discern individual places, events at those places,
and so on.

Stuart Cheshire, Apple - Zero Configuration Networking with Rendezvous

Stuart gave an overview of Zero Configuration Networking, more
commonly known by Apple's name of "Rendezvous". The presentation is
available as href="">an
Acrobat file.

In a nutshell, ZeroConf allows
services from different devices to find each other without any
explicit network configuration.

I say devices, because beyond Macs, there are TiVO Series Two
machines, network-enabled video cameras, printers, and others are
starting to implement ZeroConf.

Going back to the 1980's and early 1990's, there were a plethora
of networking protocols to worry about, such as DECNET, Xerox XNS,
and so on. Most of these have died, except for TCP/IP and AppleTalk. (and SMB...)

The point of Rendezvous is, since Wide Area Communications have
converged on IP, why not Local Area Communications too?

Stuart went on to discuss the "three legs" of Zero Conf: Addressing,
Naming, and Browsing. (this is deliberately light, as I appreciate
what the tech does, but am not up to speed on the networking intricacies
-- dls)


  • ZeroConf picks a random addr in 169.254/16.

  • It sends out an ARP request. If someone answers, it picks a new address.


  • Pick a desired name in the .local domain

  • Use Multicast DNS to issue a query to see if anyone else is using the name

  • If someone is using the name, pick another

  • mDNS has ongoing passive conflict detection

  • See draft-cheshire-dnsext-multicastdns-01.txt for much more detail.


Stuart stressed how ZeroConf has been kept deliberately simple, by
not adding a lot of configuration options. He used the phrase
"don't boil our frogs". DBoF means that if you slowly keep
adding options, pretty soon you are in very hot water and boiled.
He attributes the failure of other networking protocols over
time to DBoF.

Something I will add to the subject of Rendezvous is that it was very
much in use at the conference. If you are on a Mac, go pick up href="">Hydra. It's an editor which can
handle multiple simultaneous users in the same doc. The site touts its
use in XP (Pair Programming). Hydra 1.0 was released March 31st.
Three weeks later etech attendees were using it all over the place for
collaborative note taking, and came up with a
template to help organize the "who writes what?" aspect. My daughter and I use it at home as a sort
of IM on steroids. The new href="">iTunes 4 uses Rendezvous to
share music playlists. Another great app is href="">ClipboardSharing,
which shares text and images.

In the context of what the conference is about, Rendezvous is a very
enabling technology. It makes collaboration and sharing easy. No
fussing with computer names and addresses. There are projects underway
to get ZeroConf going on Windows and Linux. Stuart was able to show
a ZeroConf enabled web camera and a printer "just work" when plugged
into a local network. It will be very interesting to see if
Windows and Linux ZC apps start trickling out by the July OSCON.
Keep an eye on

What's your view on Grassroots, disruptive tech? Do you think the advent of ZeroConf on Windows and Linux will explode the realm of realtime, local area collaboration?