Open Source Communications Software

VTun is the easiest way to create Virtual Tunnels over TCP/IP networks with traffic shaping, compression, and encryption. It supports IP, Ethernet, PPP and other tunnel types. VTun is easily and highly configurable. VPN, Mobile IP, Shaping, etc

IGMPproxy is a simple dynamic Multicast Routing Daemon using only IGMP signalling. It's intended for simple forwarding of Multicast traffic between networks. The project is no longer maintained actively by the original author. For a more up to date version (latest patches applied), please check out https://github.com/pali/igmpproxy

Snap7, through three specialized components: Client and the inedited Server and Partner, allows you to definitively integrate your PC based systems into a PLC automation chain. Designed to transfer large amounts of hi-speed data in industrial facilities, it scales easily, down to small Linux Arm boards such as Raspberry PI. Hi level object oriented wrappers are provided, currently C/C++, .NET/Mono, Pascal, LabVIEW, Python with many source code examples. Very easy to use, a full working server example is not bigger than the “Hello world”. Many projects/makefiles are ready to run to easily rebuild Snap7 in any platform without the need of be a C++ guru. Very detailed documentation provided.

Psi is a cross-platform powerful XMPP client designed for experienced users. Psi+ is a development branch of Psi XMPP client. Project purpose: collection, refinement and writing new patches for transfer them to Psi upstream developers.

Client software for users of the Automatic Packet Reporting System amateur radio network.

Gpredict is a real-time satellite tracking and orbit prediction application. Gpredict can track an unlimited number of satellites and display the data in tables and various graphical view.

Free teleprompter software. Built with web technologies so its easy to customize. Features include: mirroring, dual-screen support, rich text editing, image support, custom styles, and auto-save.

Siproxd is a proxy/masquerading daemon for the SIP protocol. It allows SIP clients (softphones & hardphones) to work behind an IP masquerading firewall or router.

The bogofilter package implements a fast Bayesian spam filter as suggested by Paul Graham in "A Plan For Spam" <http://www.paulgraham.com/spam.html>. It is written in C. Supported platforms: Linux, FreeBSD, Solaris, OS X, HP-UX, AIX, RISC-OS, ...

FileZilla® is a cross-platform FTP, SFTP, and FTPS client with a vast list of features, which supports Windows, Mac OS X, Linux, and more. FileZilla's dynamic tools help you move files between your local machine and your Web site's server effortlessly. For example, Filezilla lets you compare your files with in-directory server files to manage file syncing. You can also tab browse between servers and transfer files to them simultaneously, as well as edit server files on the go. And Filezilla is available in 47 languages worldwide!

EiskaltDC++ is a cross-platform program that uses the Direct Connect and ADC protocols. It is compatible with DC++, FlylinkDC++, LinuxDC++ and other DC clients. EiskaltDC++ also interoperates with all common DC hub software.

Trojitá, a Qt IMAP e-mail client

Tox is a peer to peer (serverless) instant messenger that focuses on security and privacy. In today's world where digital surveillance is rampant, Tox offers users a communication software alternative that's free from prying eyes and ears, and is, quite literally free and without advertising. Tox comes with all the great features you'd expect from an instant messenger application, including voice calls, video calls, file sharing and screen sharing. Everything done on Tox is encrypted using open-source libraries so you can be assured of completely private conversations. It also has no central servers that can be raided, shut down, or forced to turn over data. There are no corporate interests, no hidden agendas-- just simple, secure and easy to use messaging.

pcapsipdump is libpcap-based SIP sniffer with per-call sorting capabilities. It writes SIP/RTP sessions to disk in a same format, as "tcpdump -w", but one file per SIP session (even if there is thousands of concurrent SIP sessions). Getting started: http://pcapsipdump.sf.net/

Rumble is a mail server suite for SMTP (ESMTPSA), HTTP, POP3 and IMAP4v1 with an extensive C/C++ and Lua API for scripting. It comes with support for SSL/TLS, SQLite and MySQL and has a web-based administration and webmail feature. Additional included modules feature greylisting, DNS blacklisting, SpamAssassin support and dynamic performance scaling as well as a multithreaded structure that allows for clustering of multiple servers for one or all domains, and with the ease of the Lua API, you can create your own new server mailing lists, CRM software, e-marketing and other extensions within minutes.

FusionPBX is a multi-tenant PBX and voice switch for FreeSWITCH, a highly scalable, multi-threaded, cross-platform communication platform. FusionPBX can be used either as a single or domain based PBX, and offers several functionalities: as carrier grade switch, call center server, voicemail server, fax server, conference server, VoIP server, multi-tenant appliance framework and so much more. It also offers unlimited extensions, device provisioning, music on hold, call parking, automatic call distribution and many other superb features. Give your company the business functionality and corporate level phone system it needs with FusionPBX!

Qtmm is a simple AFSK1200 decoder that uses the computer's sound card for input. It can be used to decode packet radio, APRS and telemetry from amateur radio satellites.

small-footprint UNIX/Linux daemon to relay multicast UDP traffic to client's TCP (HTTP) connection. This app targets home users and is designed for small-scale usage. For enterprise purposes please consider Gigapxy (gigapxy.com),

Please note that OWFS source code, and all Issue/Tickets/merge requests have now been moved to https://github.com/owfs/owfs/. Developer mailing lists will still be kept at Sourceforge. ---- OWFS -- 1-Wire file system. Use the Dallas 1-Wire and iButton chips with standard filesystem commands. Create temperature loggers. Monitor everything. OWHTTPD -- same system, only used as a light weight web server. OWFS is also ported to embedded routers, Mac OSX and Windows. Basically you can use these inexpensive little sensors and other chips with very simple wiring to sense and control the physical environment. The interface is very flexible -- everything from a web browser, to read and writing directly to the chip's "file" to integrating with your programs -- even over the internet. There is a growing number of 1-wire sensors: temperature, voltage, humidity, light, ultraviolet, pressure, thermisters, thermocouples, programmable microcontrollers, relays, lights, LCD panels, etc

Gqrx is a software defined radio receiver powered by GNU Radio and the Qt GUI toolkit. It can process I/Q data from many types of input devices, including Funcube Dongle Pro/Pro+, rtl-sdr, HackRF, and Universal Software Radio Peripheral (USRP) devices.

A Free SOCKS proxy server for Linux, macos and FreeBSD

Kiax is a softphone (soft phone, VoIP client) with a simple and comfortable user interface for making VoIP calls to Asterisk PBX. It depends on the iaxclient library to use Asterisk's IAX2 protocol for easy call configuration and audio setup.

Gammu is a cellular manager for mobile phones/modems. It contains libraries and functions for ringtones,logos,phonebook,SMS,etc. (used by external software), a command line version (with backup/restore) and SMS gateway (with MySQL and PostgreSQL supp

NSQ is a realtime distributed messaging platform that is designed to scale, and can even handle billions of messages daily. It promotes distributed and decentralized topologies, allowing it high availability and fault tolerance along with guaranteed reliable message delivery. NSQ scales horizontally and is easy to configure and deploy. It is agnostic to data format, so messages can be in JSON, MsgPack, Protocol Buffers, or anything else. Official Go and Python libraries are available, and so are many other community-supported libraries. Binary releases are published for Linux, freebsd, darwin and Windows as well as an official Docker image.

IRCD-Hybrid is a lightweight, high-performance Internet Relay Chat server.