Neil's News

DHTML Client

30 July 2005

Early in 1997 I got a phone call from someone who'd just signed up to a new ISP with a weird name: Sympatico. They were having problems connecting to SchoolNet Moo. It turned out that their ISP had provided them with a web browser and an email client, but no Telnet client! I was stunned. What kind of ISP would do such a thing? It would be like a Swiss army knife without a screwdriver.

One by one other ISPs followed suit and it slowly dawned on us that the Moo (which depends on Telnet) effectively had a death sentence against it. As people found it increasingly difficult to connect to the Moo, our stream of new users dried up. We tried everything we could think of to maintain accessibility. Webifying the Moo failed to capture the interactive multi-user essence which makes it distinct from a website. Using Java applets to connect failed due to Java's spotty implementations and firewalls which block everything but port 80. Offering a selection of free, downloadable clients failed since few people are willing to jump through hoops in order to connect to something they know nothing about.

It was Google's introduction of Gmail last year that suddenly made us realize how to solve the problem. Use DHTML to decouple the user interface from the web page; use rapid-fire HTTP requests to establish a virtual connection; use JavaScript to integrate the connection on the client-side and CGI on the server-side; use a separate server to handle the increased load. A new client has been programmed and is currently in beta. It's a cross-browser multi-threaded five-tired application. I'm still vaguely surprised that it works. Give it a spin, let me know where the rough edges are.

Browser
HTML
JavaScript
Web

Gateway server
PHP
Python
Telnet

Moo server
Moo
Canada

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Legal yada yada: My views do not necessarily represent those of my employer or my goldfish.