Free file sharing client software for linux

Ragnarok Online Client project is a client to the Ragnarok online network.
Ragnarok Online Client is a client to the Ragnarok online network, an MMORPG.
This project only provides an API to be able to program a client without having to understand the protocol itself, and to keep up-to-date just by the library.
Enhancements:
- Made it work with current iRO and improved it to be able to stay online until one kills it ... though no user interaction is implemented yet

LimeWire is a multi-platform Gnutella client with nice features like auto-connect, groups, browse host, multiple search, upload throttling, connection quality control, library management and sophisticated filtering. LimeWire is built for the both the novice and power user.
LimeWire allows you to search for multiple files at the same time, available in several different languages, and is most famous for its ease-of-use and cross compatibility.
LimeWire will run on Windows, Macintosh, Linux, Sun, and other computing platforms.
Main features:
- Ease of use - just install, run, and search
- Ability to search by artist, title, genre, or other metainformation
- Elegant multiple search tabbed interface
- "Swarm" downloads from multiple hosts help you get files faster
- iTunes integration for Mac users
- Unique "ultrapeer" technology reduces bandwidth requirements for most users
- Integrated chat
- Browse host feature--even works through firewalls
- Added Bitzi metadata lookup
- International versions: Now available in many new languages.
- Connects to the network using GWebCache, a distributed connection system
- Automatic local network searches for lightning-fast downloads. If youre on a corporate or university network, download files from other users on the same network almost instantaneously!
- Support for MAGNET links that allow you to click on web page links that access Gnutella.

Web Sharing is a small tray applet for sharing files on the web.

Publish anything on the Internet or your local area network at home, office or school from a folder on your hard disk with just a few clicks of a mouse!

Jabber is an instant messagings system (and a few other things but Ill forget about these for the moment), but it uses XML so its easy to create clients for it, and to link it in with other systems.

As well as that anyone can run a Jabber server, so youre school, university or office could have their own messaging system.

The Freiburg project is an infrastructure to replace shared libraries with a client/server interface. This system converts a shared library into a "service" using Unix or inet domain sockets for communication.
The "service" will be usable by any programming language without additional C programming requirements. An application is a composition of multiple services using an event-based message bus for communication.
A service can reside locally or remotely using the "client" or the inetd super-server for startup.
Enhancements:
API update
no libtool for build-environment
-significant speedup for build
-no libtool bug issues anymore
-no libtool porting issues anymore
update transaction work-flow
-no return-handles anymore
-no public transaction API anymore
speed improvements
-better internal caching of used objects
-improved header parsing
API now thread-safe
-need MUTEX lock for MqCreate
-need MUTEX lock for MqDelete

AFS is a distributed filesystem product, pioneered at Carnegie Mellon University and supported and developed as a product by Transarc Corporation (now IBM Pittsburgh Labs).
It offers a client-server architecture for file sharing, providing location independence, scalability and transparent migration capabilities for data.
IBM branched the source of the AFS product, and made a copy of the source available for community development and maintenance. They called the release OpenAFS.
Enhancements:
- OpenAFS 1.4.0 adds large file support in Unix and Unix-like clients and in servers.
- Kerberos 5 integration has been improved. aklog now ships with OpenAFS 1.4.0.
- Several new operating system versions are now supported, including Solaris 10 on both SPARC and Intel.

libshbuf introduces a new IPC concept: the "shared buffer", a more flexible and faster alternative for standard Unix FIFOs.
Take some shared memory, flavour it with semaphore-based locking and change notifications, and refine it with an easy-to-use API and you get libshbufs "shared buffers".
Main features:
- Normally better latency and throughput
- Full access to the buffer at any time
- Connecting processes need not to be children of each other
- Arbitrary buffer lengths
- Memory mapped
- Backlog
The implementation is based on SysV shared memory, semaphores and message queues. It makes use of POSIX pthreads.
Both an easy understandable C library and a basic Python module are provided.
Version 0.0.3 is stable and feature complete.
The concept of "shared buffers" is explicitly designed for high thoughput, low latency streaming of data (e.g. audio) between two processes, where a Unix FIFO is not enough. Thus it is optimized for exactly two connecting peers, a minimum of locking and minimum of copying of memory.
For each shared buffer two shared memory blocks, a semaphore and a messages queue are created. The first shared memory block (aka "control memory block") contains some watermark information about the shared buffer. The second contains the buffer itself.
The semaphore is used for locking access to the control block. The message queue is used for signalling the other side on changes of the buffer.
A shared buffer provider is a process which creates it with with shbuf_create(). A new key for it will be registered (the key is an integer value, the key_t of the control shm). A shared buffer client is the other side of the buffer: it opens an existing buffer with shbuf_open(key).
Only one client and one provider may be connected at once. When using the notifying feature of libshbuf a background thread is started, which listens on the message queue for certain messages. It forwards these messages to a classic FIFO. The main program may listen on this FIFO with a standard select() or poll().