Free peer to peer software for linux

GNUnet is a peer-to-peer framework with focus on providing security. All peer-to-peer messages in the network are confidential and authenticated.
GNUnet provides a transport abstraction layer and can currently encapsulate the network traffic in UDP (IPv4 and IPv6), TCP (IPv4 and IPv6), HTTP, or SMTP messages.
GNUnet supports accounting to provide contributing nodes with better service. The primary service build on top of the framework is anonymous file sharing.
The goal of the GNUnet project is to provide an infrastructure for secure peer-to-peer networking. All communication in GNUnet is authenticated and link-to-link encrypted.
The economic model makes attacks on the network harder since the economics can be used to control resource usage. GNUnet peers exchange messages using a pluggable transport service abstraction. Currently, transport services based on UDP, TCP, HTTP and SMTP are available.
The GNUnet core provides mechanisms to perform resource allocations for CPU, bandwidth and storage space. The core enforces resource limitations set by the user. GNUnet does not rely on any centralized services.
New Peer-to-Peer protocols can be easily implemented on top of the basic GNUnet infrastructure. Current protocols include anonymous file sharing, a trivial chat protocol, message throughput benchmarking and network topology visualization.
System requirements:
- GNU/Linux, FreeBSD, OpenBSD, NetBSD or Solaris.
- GNU MP Bignum Library (>= 4.0.0)
- libgcrypt (>= 1.2.0)
- gtk+ (>= 2.0)
- libextractor (>= 0.3.3)
Please keep in mind that this is a beta version. There may still be some stability, scalability and performance issues. So far the network is very small. Very little content is yet available. A subscription to GNUnet mailinglists might be a good idea.
Enhancements:
- gnunet-fuse now has support for write operations.
- The latency and performance of various database operations (for both MySQL and SQLite) was improved.
- Fixed bugs include broken error handling in the UDP transport, log rotation not deleting old log files, and crashes in gnunet-update and gnunetd.

BioCluster is a peer-to-peer clustering platform for Asterisk, the open source PBX, which allows Asterisk to be used as a full carrier-grade telephony solution. This project is meant to be installed on several machines together with Asterisk, turning them into a VoIP cluster.

While the BioCluster peer-to-peer protocol was initially designed to cater to Asterisk-based clustering solutions, the BioCluster framework is capable of being extended to support various forms of normally unclustered devices or software packages.

naim project is the original ncurses, console-based AIM client, which also supports IRC, ICQ, and Lily CMC.
For AIM and ICQ, it uses the TOC protocol, and includes many commonly-requested features found nowhere else, while still preserving naims classic look and feel.
Main features:
- naim includes unique features like zero-configuration peer to peer encryption, automatic message queueing, and incoming message modification (to correct common spelling mistakes and expand common abbreviations; see /help filter).
- naim also includes powerful dynamic module support, allowing developers to modify all major aspects of naims behavior.
- Third-party plug-ins have been used to extend naims functionality for use in embedded monitoring clients, and for use as host to automatic clients ("bots").
- The naim-modules package (distributed below) includes several example plug-ins, including a telnet server (nsocket), an interactive bot (naimusers), and a simple anti-spam measure (nantispam).
- When combined with GNU Screen, naim is great to use as a chat client as well as an answering machine. Individual users can detach, log out, pack up and go home, then log back in from anywhere on the Internet to resume their naim session.
- naim is maintained by an OPEN, DIRECTED COMMUNITY, and has been in development since October, 1998.

BLAG is a Linux distribution based on Fedora Core and reduced to one CD. BLAG Linux Distribution includes useful applications missing from Fedora Core (e.g. mp3, p2p, apt, etc...), as well as a suite of graphics, Internet, video, office, audio and peer-to-peer file sharing applications.
BLAG is up-to-date with all Fedora errata fixes at time of release and uses synaptic for easy upgrades. The name stands for Brixton Linux Action Group, which works to overthrow corporate control of information and technology through community action and to spread Free Software.
BLAG is an operating system. BLAG has a suite of graphics, internet, audio, video, office, and peer to peer file sharing applications. You can replace a windoz installation with BLAG. If you would like to install and run BLAG, download and burn it to cd.
Whats New in 60001 Stable Release:
- The first update to the BLAG 60k series, BLAG 60001, has been released. This is just a roll up of recent package updates, including an update from the 2.6.18 kernel to 2.6.20. The base package set remains the same. Over 200 updated packages are included. This release is primarily done so people who download the ISO dont have to then download a bunch of package updates. The repository now has over nine thousand packages and the developers DVD set now takes three DVDs.

MLdonkeyGtkUi provides a graphical interface to MLdonkey, a multi-platform, multi-network peer-to-peer client.
It supports several large networks such as eDonkey, Overnet, Kademlia, Bittorrent, Gnutella (Bearshare, Limewire, etc.), Gnutella2 (Shareaza), or Fasttrack (Kazaa, Imesh, Grobster).
Networks can be enabled or disabled. Searches are performed in parallel on all enabled networks. For some networks, each file can be downloaded from multiple clients concurrently.
Enhancements:
- fixes

retroshare provides a private P2P file sharing software.
Retroshare is a cross-platform private P2P sharing program. It lets you share securely to your friends, using a web-of-trust to authenticate peers and OpenSSL to encrypt all communication. RetroShare provides filesharing, chat, messages, and channels.
Main features:
- A Private Peer to Peer Network which allows you to share information with only the people you want to.
- Reliable Identification and Authentication of your friends.
- Plus an Introduction Scheme which connects you to the friends of your friends, and facilitates network growth.
- Encrypted Communication, ensuring all shared information is known only to you and your peers.
- A Communication Platform which can potentially support services such as Secure Email, File Sharing, Video or Voice over IP and Messaging
- A Decentralised Social Sharing Network designed **For the People**
- with no dependancies on any corporate system or central servers.
Enhancements:
- First release with Web of Trust Authentication!
- Downloads are automatically resumed
- New Directory search interface.