Group Annotations in NCSA Mosaic
Mosaic supports group annotations
-- annotations to documents anywhere on the network that are shared by
multiple people in a group.
This capability is intended to support workgroup collaboration --
relatively small, relatively local groups of people working together
on a common problem on the Internet. The idea is that such a group
will run a local group annotation server (or just annotation
server). Each time a member of the group accesses a document
anywhere on the Internet, the annotation server is contacted to find
out if any members of the group have posted annotations on that
document; if so, hyperlinks to the annotations (served by the
annotation server) are interleaved into the document text -- just like
with personal annotations. Annotations (both text and video) can be
posted via the normal
Mosaic annotation interface, by selecting "Workgroup Annotations"
from the appropriate option menu.
The NCSA Public Annotation Server
We have developed an annotation server (which has been released as
part of the NCSA httpd version 0.4; see here). We are
running it on an NCSA system for public access by the Mosaic/World
Wide Web community, and we encourage anyone who is interested to
configure their Mosaic setups to use it, to post annotations on it,
and to read annotations others have posted.
To tell your Mosaic about the public annotation server, put the
following line in your
If you do not have a fairly fast network link to the NSFnet backbone,
you may experience performance degradation within your Mosaic session
when you have this resource set, as the annotation server at NCSA is
being contacted each time you access a document. On the plus side,
we're sitting right on the backbone and running the server on a very
There is no security in place: anyone may edit or delete
annotations that anyone else posts. This means two things:
The current annotation server is a proof of concept. We are planning
to address the larger issues involved with a practical, trustable
system down the road.
- Please be nice and don't interfere with other people's annotations.
- Don't implicitly trust annotations that you read; author, content,
or both could have been interfered with without the real
author's consent or knowledge.
There are a number of unresolved design issues involving group- and
community-wide annotation servers. We'd love to hear your ideas --
feel free to leave a group annotation with your comments or questions!
Discussion, summaries, etc. of some of these issues will be here.