I'm sorry to say this, but that it, to some extent 'reinventing the wheel'. If you intend to do so, at least please do it properly and thoroughly (my $0.02 of wisdom) and if you are one of those believing IRC is old (I agree) then find a solution: A new protocol. And before anyone goes and says WTF are you smoking, why do something so big for something so mundane etc... And that there'd be no client apps and whatnot then let me demonstrate a simple approach to this:

1.) A stream based on Meta tags (html style type things) that way its just as versatile as your AJAX toy - and is extendable.
2.) By all means, come up with a web client (I'm all for it, cross platform, quick, open source goodness)
3.) Publish the protocol standards for GTK, QT and console developers. I'm working on a similar data transmission system over TCP/IP and UDP for a Prometheus experiment and networking in my programs (I want to get into data management and databases from scratch) - I'll write you an (or more than one) app thats cross platform and looks nice - console or GTK or whatever you like: we have a few delphi and lazarus developpers if I recall - both support networking do they not?
4.) Publicise it to the IRC communities with open source clients and whatever - it proposes all the benefits of IRC and all the things we love from that system plus the versatility of AJAX and yada without being a gizmo. Effectively, let the pascal community overhaul an international standard on its own - plain and simple.

I'll put it in a quote often overused (once more now 'No pain no gain' - this bit of effort could really help the greater community if anyone here has some ambition. Doesn't anyone ever get the feeling Pascal and related technologies is often dismissed as not fit for the real world by the C/C++ world and should stay educational only. Its a little 'unnerving' if you ask me.