Free p2p file sharing programs software for linux

Torrent Swapper is an open sourced sociable peer to peer file-sharing client based on the Bittorrent protocol that is ideal for high-speed distribution of large files that has a basic understanding of human friendships, of user tastes in content, and of Internet connectivity between users.
Torrent Swapper project supports simultaneous downloads, download queue, selected downloads in torrent package, fast-resume, speed limits, port mapping, disk cache, proxy, ip-filter, etc.
Main features:
- Amazon-like recommendations to get interesting files
- Doubling the download speed by using the upload capacity of friends
- Real-time P2P file sharing with P2P video streaming
- Showing the locations of seeders / leechers of the same content with city-level accuracy on a world map
- Multiple downloads in a single window
- Queueing system with priority
- Supporing pause, stop, resume, queue, remove operations
- Supporting global setting such as upload and download limiting
- Supporting local setting for each torrent as well
- And much more...

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.

Phosphor is a peer-to-peer file sharing program.
Phosphor can be used to search for and download files of all types as well as share your own.
A user friendly GUI combined with useful features make Phosphor one of the strong contenders in the file sharing market. Expect a more reliable, friendly, faster and efficient file sharing experience.
Main features:
- Works on all systems with Java (e.g. Windows and Unix)
- Share any file type: music, video, applications
- Advanced search options for accurate results
- Chat capabilities
- Hotlist support
- Cross server searches
- System specific features like ping and system tray
- Scalable without a large strain on the network
- Open source and non-commercial
- XML network protocol

ShmFIFO library provides an easy-to-use interface to shared memory for programs where one process needs to send blocks of data to other processes.

It was developed because pipe(2) and mkfifo(3) have a very small buffer size (4k) and are unsuitable for many applications. Shmfifo allows you to put a block of data in shared memory, get the oldest block of data from shared memory.

ShmFIFO library also has the feature to share one instance of a private data structure among all processes which use the library.

How to use shmfifo

Before using, shared memory should be created. After creating shared memory, process which wants to use it, should attach to memory. Then it can put and get blocks to FIFO. After process is finished working with FIFO, it calls shfifo_detach. When no processes will use FIFO, shared memory should be deallocated.

Usally, lifecycle of shmfifo-based program is following:

[parent] shmfifo_create
[parent] fork(2)
[both] shmfifo_attach
[both] shmfifo_put, shmfifo_get (many times)
[both] shmfifo_detach
[parent] wait(2) or waitpid(2)
[child] exit
[parent] shmfifo_dealloc

shmfifo comes with test.c program, which is good sample of how to write programs with shmfifo. It forks into 2 processes, parent generated variable-length blocks, writes checksum into each block and put it into FIFO. Child gets blocks from fifo, check if checksum is valid (its always valid if there is no bug in program) and prints debug info. after large number of blocks gets transferred, both processes are exit.

Additionally, shmfifo allows processes to share one private structure. test.c uses this structure to store counter, which is increased each time when parent cannot put block to FIFO because its already full and has to wait until child will get block. If small amount of memory allocated for FIFO, then parent will wait more often.

Installation:

make
make test
su -
make install

test.c is sample test program which is builts into test binary. You can run it to test if library is working

Valknut project is a peer-2-peer file-sharing program (similar to Kazaa, Soulseek or eDonkey) that uses the Direct Connect protocol.
It is compatible with other DC clients, such as the original DC from Neomodus, and DC++.
Main features:
- open source
- multiplatform (Linux,Win32,OSX ...)
- multilanguage
- multihub connections
- multihub search
- multi-/chunkdownload (download one file from multiple sources at the same time)
- firewall support
- sounds
- favorite hub list
- online translator
- load/save search results
- autosearch new sources
- socks support for linux (http://www.inet.no/dante/)
- proxy support for hublists
- support bz2 share lists
- support xml share lists
- support ssl transfers
- support ssl hub connections (e.g. hub use sslproxy)
- support secure chat (not secure against "Man In The Middle Attack")
- chat emoticons
- tiger tree hash (TTH) support

LX is a community-driven Web site program in which users can share links, post on forums, send private messages to one another, and more.

LX is written with performance, security, standards, and usability in mind.

Hybrid Share is a User Friendly Application for Linux, Mac and Windows users, that allow you to Share file (and Talk) instantly with your friends...

What is Hybrid Share ?

Hybrid Share is a simple (User Friendly) Mono C#/Gtk# Application that allow Mac, Windows and Linux Users To Share Files. The Application is extensible via Plugins, so you can Talk with connected people, check your mailbox or other things that plugins could do.

What do you use if you have to share files with your friends ?

E-Mail or Instant Messaging are the first possible solution, but the E-Mail Size block and the slowing of the IM make this channels bad to share files. The NFS (Network File System) or other system like this, works only between similar system or are a little bit difficoult to configure, the same for ftp server.

So The Solution is Hybrid Share that is Portable and Easy to Use, It isnt the Best Application in The World, but it does a useful work.

What is the Difference with a Normal P2P ?

Hybrid Share has a core of P2P but is more like a traditional IM (Instant Messenger), like GTalk, MSN, Gaim, Adium and so on.... No Network Configuration is needed, Youve only to add your "buddies" (like an IM) and Drag File Into their folders...