Free communication software for linux

Genoa Active Message MAchine is a low-latency, high-throughput driver wrapper for the Linux kernel, using Active Ports (a version of Active Messages).
Genoa Active Message MAchine runs parallel to the IP stack and is designed for LANs only.
Main features:
- A low latency, high throughput communication system for clusters of PCs
- Supports both single and dual CPU processing nodes (Intel IA-32 or x86_64)
- 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
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), or x86_64 processors (AMD Athlon64, AMD Opteron, Intel EMT-64), 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.
A porting of MPI atop GAMMA is available, called MPI/GAMMA.

CryptoCD is a collection of software that provides secure communication through the Internet. The programs cover tasks like email encryption, secure chat, and anonymous Web browsing.
CryptoCD comes with comprehensive documentation explaining step by step installation and use of the software for unexperienced users. The project focuses on German-speaking users.
Enhancements:
- This release has been updated to Firefox 2.0.0.5 (OS X and Windows), Thunderbird 2.0.0.5 (Windows) and 1.5.0.12 (OS X), Enigmail 0.95.2 (Windows) and 0.94.4 (OS X and Linux), and Vidalia 0.0.12 (OS X and Windows).
- The documentation was also updated.
- This version comes with a new cover.

libbehate is a library with implementation of BHT communication protocol.

This protocol is used in communication with Toyota Denso data collection terminals. Library itself uses librs232 for link layer.

Library is released under the term of LGPL license.

LUX4 is a powerful and fast communication protocol for Remote Procedure Call (RPC). LUX4 library provides both Client and Server classes.
C/C++ porting is planned but for the Client side only. LUX4 performances are far ahead of other RPC protocol like RMI.
Enhancements:
- First Open Source release.

OpenDMTP is a protocol and framework that allows bi-directional data communications between servers and devices (clients) over the Internet and similar networks.
OpenDMTP is particularly geared towards Location-based information (LBS) such as GPS, as well as temperature and other data collected in remote-monitoring devices. OpenDMTP is small, and is especially suited for micro-devices such as PDAs, mobile phones, and custom OEM devices.
We saw a need for a communications protocol that allowed high-latency, low-bandwidth (HL/LB) devices to transmit location data to monitoring-systems. Because these devices often have limited network connectivity, the protocol needed to be small and efficient.
Example devices include mobile phones, PDAs, OEM micro-devices (alarm systems, temperature monitors, etc.), and more.
There are many mobile GPS tracking devices on the market today with their own closed proprietary protocols. Searching the web for open protocols revealed only a few available for transferring data (including GPS information) between devices.
However these solutions are generally designed for non-mobile applications and lack some of the low-bandwidth, configurable, and extensible features that mobile applications require.
Main features:
Small Footprint: Mobile devices typically have limited resources on which to run client code (ie. memory, processor speed). An open protocol designed with this in mind should be optimized to allow efficient implementation and should support devices such as PDAs, mobile phones, GPS monitoring devices, and other OEM micro-devices.
Network Efficient: Because mobile devices typically have limited network connectivity, the protocol needs to be efficient in its dialog between the client and server. The communication needs to be optimized such that the necessary information can be conveyed with a minimum number of bytes in the least amount of time.
Bi-directional: Some devices can support two-way communication (ie. GPRS, or other socket based connections), while others may only support one-way communication (ie. some satellite communication systems). With this in mind, a protocol should be designed to support both duplex (two-way) and simplex (one-way) communication.
Transport Media: Differrent mobile applications will have their own unique way of communicating data back to the server. Some may use GPRS, or socket based communication, others may use satellite communication, while still others may use other forms of wireless communication, such as BlueTooth. The design of the protocol should be able to encompass all such transport media types, regardless of the type of transport in use.
Flexible Data Encoding: Most types of transport media allow for the transmission of binary encoded data. However, there may be some forms of media for which an ASCII encoded data packet is much better suited. A protocol designed with this in mind should be able to support both types of data encoding.
Configurable Messages: Due to the broad range of data types used in mobile applications, the protocol should be flexible enough to define standard messages, yet still allow custom messages within the framework.
Extensible: Not every mobile application is the same. Some require special handling and may have various types of inputs and outputs. A protocol designed for mobile applications should insure that the framework can be easily extended to incapsulate the specific needs of the device.
Industry Compatibility: Having an open protocol insures better compatibility between different client devices and service providers.
Reference Implementation: Having a reference implementation that showcases the major features of the protocol provides an easy starting point on which developers can add their own features and platform specific implementation without having to worry about how data gets from the client to the server.
Enhancements:
- Added additional logging for any errors returned by closedir, fflush, fclose.
- Additional changes made to facilitate dual transport support.
- Property PROP_COMM_HOST no longer uses localhost as a default. Also, if this property remains undefined during deployment, no events will be queued.
- When Geozone arrival/departure delay is in effect, the generated event will be the time and GPS fix of the moment that the geozone boundary crossing was detected.

Palava is a communication protocol to build Web applications using PHP and Java. The project allows you to build modern 3-tier architectures, where PHP runs on the frontend servers and Java runs on the backend.
It consists of a Java backend server to handle the communication, providing a component deployment mechanism, and a PHP library to access backend jobs from the frontend(s). Palava makes it easy to reuse existing Java business logic in easily created, modern PHP frontends.
Palava is not a full blown Web site framework, but instead encourages the use of existing frameworks like CodeIgniter.
Enhancements:
- This release adds generic JBoss support.
- It uses the build.jboss file to build a bean.
- There are minor bugfixes.

system-config-printer configures a CUPS server. The project uses the CUPS API (bound to Python with pycups) to do this.
The communication with the server is performed using IPP. As a result, it is equally able to configure a remote CUPS server as a local one.
Enhancements:
- Some fixes have been made for saving unapplied changes, and the "job-hold-until" attribute can now be set.