Free communication software for linux

Inter-Thread Communication (ITC) aims to make it exceedingly easy to call functions in other threads.
The lexer does all the work, so just run the lexer on your headers, then call the stub functions.
In addition, it also provides a complete threading API, with the four threading primitives and a high speed threadsafe FIFO class.
Enhancements:
- It add support for GCC 4.x, and the build system is fixed.

Ice, the Internet Communications Engine, is middleware for the practical programmer. A high-performance Internet communications platform, Ice includes a wealth of layered services and plug-ins. Ice means simplicity, speed, and power.
Ice is available under the terms of the GNU General Public License (GPL). Commercial licenses are available for customers who wish to use Ice with proprietary products. Please contact sales@zeroc.com for more information.
Ice is currently available for C++, Java, C#, Visual Basic, Python, and PHP, and is supported on various operating systems. Additional operating systems and languages will be supported in future releases.
Ice consists of the following packages:
Slice The Specification Language for Ice. Slice establishes a contract between clients and servers, and is also used to describe persistent data.
The Slice Compilers Tools to compile from Slice into target languages, such as C++ and Java, or to automatically generate documentation from Slice files.
Ice The Ice core library. Among many other features, the Ice core library manages all the communication tasks using a highly efficient protocol (including protocol compression and support for both TCP and UDP), provides a flexible thread pool for multi-threaded servers, and additional functionality that supports extreme scalability with potentially millions of Ice objects.
IceUtil A collection of utility functions, such as Unicode handling and thread programming. (C++ only.)
IceBox An application server specifically for Ice applications. IceBox can easily run and administer Ice services that are dynamically loaded as a DLL, shared library, or Java class.
IcePack A sophisticated server activation and deployment tool. With IcePack, the complex task of deploying applications in a heterogeneous computer network is dramatically simplified. Simply write a deployment descriptor in industry-standard XML, and IcePack handles the rest.
Freeze Freeze provides automatic persistence for Ice servants. With just a few lines of code, an application can incorporate a highly-scalable evictor that efficiently manages persistent objects.
FreezeScript It is common for persistent data types to change, especially in large software projects. In order to minimize the impact of these changes, FreezeScript provides inspection and migration tools for Freeze databases. The tools support an XML-based scripting capability that is both powerful and easy to use.
IceSSL A dynamic SSL transport plug-in for the Ice core. It provides authentication, encryption, and message integrity, using the industry-standard SSL protocol.
Glacier One of the most difficult challenges for object middleware systems is security and firewalls. Glacier, the firewall solution for Ice, greatly simplifies the deployment of secure applications. Glacier authenticates and filters client requests and allows callbacks to the client in a secure fashion. In combination with IceSSL, Glacier provides a powerful security solution that is both non-intrusive and easy to configure.
IceStorm A messaging service with support for federation. In contrast to most other messaging or event services, IceStorm supports typed events, meaning that broadcasting a message over a federation is as easy as invoking a method on an interface.
IcePatch A patching service for software distributions. Keeping software up-to-date is often a tedious task. IcePatch automates updating of individual files as well as complete directory hierarchies. Only files that have changed are downloaded to the client machine, using efficient compression algorithms.
Enhancements:
- Various additions, including redundant IceGrid registries.

SAP R/3 Communications Suite allows SAP R/3 servers to communicate with external devices such as fax and GSM modems by sending and receiving a fax or SMS.

SAP R/3 Communications Suite provides an easy configuration through a Web interface and a JMX console.

Buni Meldware Communication Suite (MCS) is a platform-independent groupware package consisting of:
- Meldware Mail
- Meldware Calendar
- Meldware Webmail
- Meldware Secure Administration System
Together the package provides support for thousands of users concurrently to send and receive email and to schedule meetings. MCS uniquely allows you to store all messages and scheduling events in nearly any database and runs on nearly all popular software and hardware platforms.
MCS commitment to platform and database agnosticism aims to meet increasing business requirements to maximize ease and flexibility of managing and accessing data as well as putting a premium on interoperability.
Additionally, while the scheduling and calendaring services can be installed separately, the integrated feature set provides both a distinctive and powerful experience to both users and server-side Mail Based Applications and Collaboration Based Application Services.
The MCS platform provides security integration using LDAP sources including Microsoft Active Directory as well as flat-file and database sources.
Additionally, extensible security allows custom authentication/authorization sources.
Enhancements:
- This is the first milestone release with WCAP, freebusy for webmail, and mature IMAP all together.
- It has undergone extensive hardening, dogfooding, and QA testing.
- The WCAP protocol for calendaring now works well for Thunderbird and Lightning 0.3.
- Webmail calendaring was greatly improved.
- The abillity to download attachments has been added to the webmail interface.
- Numerous performance improvements have been made in SMTP, IMAP, and MIME parsing since 1.0-M7.

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

ICMP-Chat is a simple console-based chat that uses ICMP packets for communication. All the data is encrypted with Rijndael-256 algorithm.
Installation:
Type: make && make install
For solaris type: make solaris && make install
Usage:
Usage: icmpchat [OPTIONS] < host > < nick >
< host > = Host to chat with
< nick > = Your nickname
OPTIONS:
-t < type > = specify icmp type (default ECHO_REPLY)
Example: icmpchat 192.168.1.2 foo
ICMP codes:
[0] Echo Reply
[5] Redirect
[8] Echo Request
[9] Router advertisement
[10] Router solicitation
[13] Timestamp request
[14] Timestamp reply
[15] Information request
[16] Information reply
[17] Adressmask request
[18] Adressmask reply
Enhancements:
- Rewrote from scratch
- Implemented optimized rijndael algorithm
- Implemented sha256 for password hashing
- Implemented ncurses frontend (again)
- Fixed getuid problem so that setting suid flag works now (thanks John)

SpeexComm is a Speex based multiplatform voice communication engine meant mainly for gaming. The project is written in C99. The engine itself depends only on libc but e.g. ALSA and Speex libraries are recommended for audio input/output and voice encoding/decoding. The engine is accompanied with some reference UIs.
Main features:
- Free: libre and gratis
- Portable: the engine itself depends only in (uc)libc
- Lightweight: engine does little work (no mallocs, not many memcpys), audio encoding/preprocessing can be heavy
Open Issues
- Add new parameter for audio_read/write calls to obtain information about getting behind/going ahead?
- Should client_version be given to engine_alloc as a mandatory parameter?
- If server uses struct sample for downmixing the stream from clients, there will be nothing but cache misses with smaller CPU cache. It should be easy enough to work this over by changing the way we receive data.
- Fix USE_POOL in list.c (wnd)

The ORTE is an implementation of the RTPS communication protocol defined by Real Time Innovations.

RTPS is an application layer protocol targeted to the real-time communication area. It is built on top of a standard UDP stack.

This protocol is being submitted to the IETF as an informational RFC and has been adopted by the IDA group.