Thanks for the links. Of those, I'd only ever heard of MatLab.

For the type of plotting I'm interested in, these highly sophistacated products are overkill. With sophistication, comes complexity and learning curve. were they free products, they might be worth considering, but this isn't important enough to sepnd money on. I already know how to produce the types of plot I am interested in using the simple API of GD. It does all I need.

The only addition I am looking for is the ability to watch the plots evolve in real-time, rather than only seeing a static image of the final result. To this end, the browser and Canvas tag can provide this ability, and has a sufficiently simple api that the learning curve is minimal.

The final parts of the task, and that I was asking about, are:

1. Avoiding the need for a webserver.

   This is fairly easily achieved by running a simplified server in a thread, that can server to the browser, but without the need to be able to service more than one concurrent client. And without imposing the stateless nature of http on the interactions.

2. Avoiding the need to write code in another language (Javascript).

   I intend to achieve this by proxying the Canvas API within a perl object that talk to the browser via the server-in-a-thread.

I'm still working out how to do handle push within the (minimal & standardised) Javascript that will be served along with the HTML; and getting to grips with ajax for the browser interactions, but it just takes time.