To implement a chat network like Jabber on Gnutella network, would it be technically possible?

Hm.. I dont know Jabber, is it a centralised system?
Implementing chatsystems in decentralised networks is quite hard because its hard to syncronise all messages.
Few clients already support a *chat*, but only a chat where two users can participate, plus you have to know the IP of the other user...

Building in IM services is hard to because many users have
dynamic IPs so you cant check if they are online since they dont log in on a central server.

Jabber won't be implemented into gnutella, since Jabber is a chat/IM protocol and gnutella is a file-sharing protocol, so they don't have much in common.

It's the client vendors decision if they want to add jabber support to their clients, but I don't think many of the developers would seriously consider adding jabber support in the near future.

Oh I thought this question was more theoretical,
if it was possible to build in a jabber-like IM chat.

Everything is possible - theoretically ;-). I think I remember a posting on the GDF about some fancy CHORD based chat client...

I like Gnucleus's chat module. It uses IRC to search for other Gnutella nodes, as well as for chatting.

IRC is centralized, that's why I don't like it at all.

Then you dont like GWebcache & Bootstraps too?

I don't know what you mean by centralized - there are over 390 IRC networks running on over 3687 servers. Some IRC networks have over 50 servers, many in different countries. Gnucleus cycles through networks and servers - it tries connecting, if it can't, it tries another one. This works automatically for host finding, and it would probably work OK for chat as well if it was done in a linear, logical fashion. Edonkey2000 uses IRC as well.

Then look it up.