>Agreed. While the Web needs a way to handle stateful transactions,
>such "session" capabilities must be added with *great* care.
I'm not as certain about this as I formerly was. Perhaps we should think
of stateful protocols as something that should be implemented in
task-specific helper applications.
Our Topic Information Agent for Mosaic (the work that we announced with
Spyglass at Internet World) is essentially a helper application for search,
retrieval and various other information agent tasks. However, we've also
recognized that once we have our agent software on the client, our Topic
Agent Protocol is available, so we can establish a TAP connection to a
Verity server, taking advantage of TAP's strengths for search, etc. agent
applications; TAP includes sessions, statefulness, etc.
An interesting paradigm seems to be emerging. HTML and HTTP are the
default document type/user interface and protocol, so that Mosaic (and its
ilk) can remain the centerpiece of Web usage, but helper applications can
add new document types (Acrobat, SGML, etc.), user interface features and
protocols.
Certainly we've all long accepted viewers as a means to add new document
types. Is it unreasonable to think of viewers as also having the ability
to add function-specific UI features and protocols? I hope so, since
that's what seems to be happening. It's the old "flock of collaborating
applications" idea that floats through here periodically, except that
Spyglass' business strategy is helping to make Enhanced Mosaic, in
particular, the leader of the flock (shepherd?). As long as a Web client,
speaking HTTP and viewing HTML, is at the center, we don't lose the
advantages of the global standards. E.g., Topic Agent for Mosaic always
bounces you back to Mosaic when you want to view and navigate HTML.
For example, our Web server is usable by any HTML/HTTP client that supports
forms. However, the features we can deliver are greatly limited by HTML
and HTTP. Customers who want the rest of our features can buy our TAP
communications module (which is a server unto itself; you can start with
TAP and add the Web module after) and distribute Topic Agents for Mosaic to
their users. The result is that while maintaining compatibility with the
Web's standards, they can offer significantly enhanced capabilities to at
least some of their users.
This approach seems fundamentally good to me from the standpoint that it
helps HTML and HTTP from trying be all things to all people.
Nick