what gnutella client source code do you recommend?
 

Hi, I'm trying to find a gnutella client written in C. I want the source code, so that I can make some changes and try something for a research project I have. Do you recommend me any?
Thanks

This might be what you're looking for: Gnucleus

GTK-Gnutella could also be a good fit, especially since it is still actively developed: gtk-gnutella - The Graphical Unix Gnutella Client

I'm trying to find a gnutella2 client written in Java. I want the source code, so that I can make some changes and try something for a research project I have. Do you recommend me any?
Thanks

*begin injoke, skip if you wish so*
There is no Gnutella2 in Java.

And there is no Gnutella2.

But even if there where a Gnutella2, there wouldn't be one in Java.
*end injoke*

There are some implementations of Gnutella in Java, but none of those implements the network touted gnutella2 (which is no predecessor of gnutella but just shares some common ideas - the name created quite some aversion among Gnutella developers).

If you're interested in doing research on decentral tag based p2p networks (i.e.: Gnutella), please grab a copy of Phex:
- Phex - Home - The Main Website.
- Subversion - PhexWiki - The most recent sources.

And if you're interested in the backgrounds, please have a look at Gnutella for Users and the Gnutella Specification:
- Main Page - Gnufu - Gnutella for Users - a guide to the inner workings of the network for non-programmers.
- Gnutella Protocol Specification - Gnutella Specification - The Gnutella Specification.

I'm glad to be able to help.

Best wishes,
Arne