Free communication software for linux

The RealizationEngine is designed from the ground up to facilitate group communication and collaboration.
It will store that communication to built and manage an institutional knowledge base. It is accessible from any Web browser or Web-enabled device.
Classified information is easily restricted to authorized individuals. Information can be compartmentalized, restricted, or published openly, as appropriate, all from the same system.
Ideas are coherently threaded, and every message is searchable in a single location and in the context of the messages related to it.
Main features:
- Communication base (completely replace e-mail or even Lotus Notes)
- Collaboration
- Idea Management
- Project Management
- Intranet
- Extranet
- Virtual meetings
- Online communities
- Virtual companies
- One or all of the above in a single installation

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

libstrophe is a library for XMPP client and component communication. Our goal is to build a library that is portable, usable quickly, reliable, well documented and that implements the XMPP specification.
Main features:
- XMPP compliant
- Platform agnostic
- TLS support (coming soon)
- SASL DIGEST-MD5 and SASL PLAIN authentication
- Legacy jabber authentication
- Resource binding
- Low-level miniDOM access for manipulating stanzas
- Event handers for timed events, stanza names and/or namespaces, stanza ids
- Threadsafe (coming soon)
- High-level stanza object manipulation and handling (coming soon)
- Full documentation (coming soon)
- Customizable logging and allocation facilities
- C++ binding (coming soon)
Enhancements:
- fix a bug in the fallback to jabber auth that prevented login to jabberd 1.4 servers
- Simplify access to the default loggers, and merge the basic_logging and basic examples
- draft C++ api

GAMMA is a low latency, high throughput communication system for clusters of PCs.
Network Of Workstations (NOWs) and clusters of PCs interconnected by modern, industry-standard LAN fabrics (Gigabit Ethernet, Myrinet, SCI) and running the Linux operating system, have became an attractive and cost-effective architecture for parallel and distributed applications.
The usual drawback of a standard PC cluster is the poor performance of the support to inter-process communication over the interconnect.
Current implementations of industry-standard communication primitives, APIs, and protocols, usually show high communication latencies and low communication throughput.
We have developed a system for inter-process communication, called the Genoa Active Message MAchine (GAMMA). GAMMA runs on Linux clusters of PCs with Intel IA-32 processors (Intel Pentium, AMD K6, and superior models), networked by a Gigabit Ethernet.
The core of GAMMA is a custom Linux network device driver, which operates the Network Interface Card (NIC).
The GAMMA driver delivers low latency, high throughput communication services based on Active Ports, a mechanism derived from Active Messages.
Both point-to-point and broadcast communications are provided. Broadcast communication exploits the Ethernet broadcast directly.
The GAMMA driver is able to manage standard IP traffic as long as no parallel job is running. Therefore, all IP services are up and running whenever the cluster is not in use by any parallel job.
The communication mechanisms implemented in the GAMMA driver are made available to application writers through the GAMMA user library.
The GAMMA library provides support to application launch, process grouping, point-to-point/broadcast communications based on the Active Ports mechanisms, and some collective routines (barrier synchronization, and broadcast).
GAMMA provides two levels of QoS. The lower one, corresponding to the fastest communications, is a best-effort service. With this service, network congestion and ``hot spots may cause the receiver NIC or even the LAN switch to loose packets by overrun.
The other QoS level provides flow-controlled communication, ensuring reliability up to hardware faults, at a negligible performance penalty.
Installing the GAMMA driver requires only two small and marginal patches to the original Linux kernel. The Linux kernel extended by the GAMMA driver must be installed on each PC in the cluster.
Main features:
- Supports both single and dual CPU processing nodes (Intel IA-32)
- Runs on Gigabit Ethernet
- SPMD parallel processing with message passing
- Can run IP traffic when not in use
- Good programmability thanks to fairly high abstraction level
- Reliable thanks to mechanisms for retransmission of missing packets
- Implemented as a network device driver for Linux 2.6, and released under GNU GPL
Version restrictions:
GAMMA allows more process instances of the same parallel job to run on the same CPU. Thread safety is granted with point-to-point communications when running on distinct GAMMA ports.
However, collective routines (barrier synchronization, and broadcast) are not thread compatible, as they use predetermined GAMMA ports.
The packet retransmission mechanism is not perfect. It will not work if the missing packet originates from a non-blocking send.

Libshout library allows applications to easily communicate and broadcast to an Icecast streaming media server.
It handles the socket connections, metadata communication, and data streaming for the calling application, and lets developers focus on feature sets instead of implementation details.
Enhancements:
- This release includes support for the Speex voice codec, as well as a timing fix for Theora streams and bugfixes when login fails.

Lua Messaging Engine (LuME) is a set of scripts that offer abstract functions for communication via AOLs OSCAR protocol (as used by ICQ and AIM clients), Microsoft Messengers MSNP, and Yahoos YIM protocol. Lua Messaging Engine also includes utility functions for string operations, SHA hashing, and basic HTTPS communication.

An increasing number of software developers are making use of the simplicity and power behind employing a Lua script interface.

Meetroduction, LLC has been using a Lua script interface as a core design concept for the multi protocol messaging component of its proximity based people finder client: Meetro. Beyond that, the interface offers its users a flexible way to vastly extend the clients functionality.

palmfs is a PalmOS filesystem access software for Linux, based on FUSE. It consists of two parts, a client and a server.
The client is a FUSE-based application running on the Linux system. The server part is a PalmOS application that actually executes commands sent by the client.
palmfs filesystem is intented to support various communication ports and to access the PalmOS internal filesystem as well as expansion cards.
Enhancements:
- Basic functionality was implemented.