Does any one know were you can find the current protocol specs like 0.6. Every one still gives reference to the old .4 protocol and gnutella doesn't even use TCP any more, right?

I don't think it's been fully documented yet, but you can find out more information about it at the Gnutella Developer Forum (http://groups.yahoo.com/group/the_gdf).

You also find some links for possible extensions at Limewire (http://www.limewire.com/index.jsp/tech_papers):

Handshaking Protocol http://groups.yahoo.com/group/the_gdf/message/2010
Ping/Pong Scheme http://www.limewire.com/index.jsp/pingpong
MetaData Proposal http://www.limewire.com/index.jsp/metainfo_searches + MetaProposal2.htm
Query Routing http://www.limewire.com/developer/qu...%20routing.htm

PS: Don't forget there are even more ideas coming up, like Superpeer, Swarming and Hashs!
PPS: Hashs at the GDF are called "HUGE" (Hash/URN Gnutella Extensions), e.g. link 1 link 2
PPPS: Here is the current (old) version of the Gnutella Protocoll http://www.clip2.com/GnutellaProtocol04.pdf ...and TCP will be still used.

don't bother with the clip2.com link. clip2 is dead.

The linked protocoll v0.4 document is still there. Any official mirror?

Ah thank god, the GDF has a new moderator and he cleaned up the mess. *g* I think this gives a good overview on new GDF extensions (you must be subscibed to yahoo, unfortunately):

http://groups.yahoo.com/group/the_gd...s/Development/
http://groups.yahoo.com/group/the_gd.../proposals.htm