Open Source Windows Communications Software
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Communications Software for Windows
View 1321 business solutionsBrowse free open source Communications software and projects for Windows below. Use the toggles on the left to filter open source Communications software by OS, license, language, programming language, and project status.
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qBittorrent
A free and reliable P2P BitTorrent client
An advanced and multi-platform BitTorrent client with a nice Qt user interface as well as a Web UI for remote control and an integrated search engine. qBittorrent aims to meet the needs of most users while using as little CPU and memory as possible. -
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WinSCP
WinSCP is a free SFTP, SCP, S3, WebDAV, and FTP client for Windows.
WinSCP is a popular free file manager for Windows supporting SFTP, FTP, FTPS, SCP, S3, WebDAV and local-to-local file transfers. A powerful tool to enhance your productivity with a user-friendly interface and automation options like .NET assembly or batch file scripting. Use WinSCP also for file editing, directory synchronization and site management. WinSCP is open-source and well documented. It is available in English and many other languages. -
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Scrollout F1
An easy-to-use anti-spam email gateway
• Designed for Linux and Windows email system administrators, Scrollout F1 is an easy to use, already adjusted email firewall (gateway) offering free anti-spam and anti-virus protection aiming to secure existing email servers, old or new, such as Microsoft Exchange, Lotus Domino, Postfix, Exim, Sendmail, Qmail and others. • Built-in multilayer security levels make configuration effort equal to a car radio. • It combines simplicity with effective protection using powerful open source with additional set of rules & filters. • Available as 64bit: - ISO image (Internet connection required during installation) - install from scratch (Internet connection required during installation). • Minimum Requirements (for 5,000 messages/day): 1 GB of RAM 30 GB storage drive 1 Processor x86/AMD64 1 Ethernet x 1 IPv4 address UDP ports: 53 123 4500 6277 24441 TCP ports: 25 80 443 2703 -
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tn5250
5250 telnet client
tn5250 emulates a 5250 terminal or printer over telnet, for connecting to IBM Power Systems, iSeries and AS/400 computers running IBM i, i5/OS and OS/400. It runs on any Unix or Windows system. Note that this project is now on GitHub at https://github.com/tn5250/tn5250 -
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Anti-Spam SMTP Proxy Server
Anti-Spam SMTP Proxy Server implements multiple spam filters
The Anti-Spam SMTP Proxy (ASSP) Server project aims to create an open source platform-independent SMTP Proxy server which implements auto-whitelists, self learning Hidden-Markov-Model and/or Bayesian, Greylisting, DNSBL, DNSWL, URIBL, SPF, SRS, Backscatter, Virus scanning, attachment blocking, Senderbase and multiple other filter methods. Click 'Files' to download the professional version 2.8.1 build 24261. A linux(ubuntu 20.04 LTS) and a freeBSD 12.2 based ready to run OVA of ASSP V2 are also available for download. NOTICE: V1 development has been stopped at the end of 2014 (1.10.1 build 16060). Possibly there will be done some bugfixing in future. Please upgrade to V2, which is and will be actively maintained. -
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eMule
A free peer-to-peer (P2P) file sharing client
eMule is a free peer-to-peer (P2P) file-sharing client for Microsoft Windows that was launched in 2002 as an alternative to eDonkey2000. To date, eMule is one of the world’s largest and most trustworthy P2P file-sharing clients. eMule includes advanced search features, file checks for corruptions while downloading, a preview while downloading function, and a credit system to reward frequent uploads. -
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Matroska is an open standard audio/video container format. Visit our homepage at http://www.matroska.org
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WS - Digital Mode Suite
formerly known as WSJT-X Improved
WS is an innovative suite of programs for weak-signal digital communication in amateur radio by Uwe Risse DG2YCB et al., formerly known as WSJT-X Improved. WS grew out of WSJT-X by Joe Taylor K1JT, Steve Franke K9AN, Bill Somerville G4WJS, Uwe Risse DG2YCB and others (https://sourceforge.net/projects/wsjt/). The WS Suite consists of three programs: WS (the main program), WS-MAP (wideband Q65 monitor) and EME65 (wideband JT65/Q65 for EME). The WS main program supports FT8, FT4, FT2, JT4, JT9, JT65, Q65, FST4, MSK144, WSPR, FST4W, and Echo. Notes: The WS Suite is licensed under GNU GPL v3 (https://www.gnu.org/licenses/gpl-3.0.txt). I am not aware of any adverse effects. However, use it at your own risk! WS, including its logo and all program components, is protected by copyright. Any use or modification of the code or parts thereof (e.g., the adaptation of individual program functions), is permitted only if the origin of that function or code is clearly indicated. -
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BeeBEEP (Free Office Messenger)
You can message and share files inside your intranet without a server.
BeeBEEP is a free, open-source, peer-to-peer (P2P) desktop LAN chat and office messenger built with end-to-end encryption (Rijndael Algorithm, AES). Designed for local area networks, this free cross-platform messaging app enables instant messaging, group chat, and secure file sharing across your office, home, or intranet—completely serverless and offline. Whether you need a private LAN chat application for your team or a secure office communicator over VPN, BeeBEEP operates without central servers or cloud dependencies. It is a free, serverless chat solution for Windows, Linux, and macOS where privacy, data security, and local network communication are essential. -
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IssabelPBX
Issabel PBX - Unified Communications
Open Source and Unified Communications partners created a new platform based on an Elastix® fork (currently purchased by 3CX) to provide the community with continuity, peace of mind and support needed to continue with their PBX and operation developments. Contribute to the funding of Issabel on https://www.patreon.com/issabel -
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WSJT
Weak signal ham radio communication
The WSJT project implements software for amateur radio communication using state-of-the-art digital techniques. Typical applications involve "DXing" at LF, MF, HF, and VHF+ frequencies, including meteor scatter and EME ("moonbounce"). Major emphasis is placed on weak-signal techniques. Summary Program Descriptions: WSJT-X supports the communication protocols FST4, FT4, FT8, JT4, JT9, JT65, Q65, MSK144, WSPR, FST4W, and Echo, each optimized for different sorts of radio-wave propagation. MAP65 and QMAP are designed for EME at VHF and higher frequencies. MAP65 provides a panoramic, polarization-matching receiver for the Q65 and JT65. modes. QMAP works together with WSJT-X to provide a panoramic receiver for Q65 modes covering a 90 kHz sub-band. Programs WSJT and WSPR are interesting primarily for historical reasons. They are superseded by WSJT-X. -
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aMule stands for all-platform eMule file-sharing program. It is affiliated with the eMule project and was forked from xMule on 08/2003. It connects to the eDonkey2000 network, supports Linux, Mac, Solaris, *BSD platforms, and nearly every processor arch. For development, feature requests, issues and bug reporting, go to the GitHub project page at https://github.com/amule-org/amule .
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FileZilla®
A fast cross-platform FTP client
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! -
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Telegram Desktop
Telegram Desktop messaging app
Telegram Desktop is the official C++/Qt-based cross-platform client for Telegram, implementing the full Telegram API and MTProto protocol for secure messaging, voice/video calls, file sharing, and chat features. It provides message sync across devices, supports themes, stickers, bots, and is actively maintained. -
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The portable Universal Plug and Play (UPnP) SDK provides support for building UPnP-compliant control points, devices, and bridges on several operating systems. The main repository is at GitHub in https://github.com/pupnp/pupnp. This is just a clone repository for legacy reasons. Old SourceForge repo: git://pupnp.git.sourceforge.net/gitroot/pupnp/pupnp
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RealTerm: Serial/TCP Terminal
Serial and TCP terminal for engineering and debugging
Serial terminal program for engineering. Ideal for development, reverse engineering, debugging, datalogging and capture, and automatic test. The website is a comprehensive manual for Realterm. It has an comprehensive ActiveX/COM automation support so it can be used a serial component by other programs. An extensive commandline interface supports batch files and simple automatic test programming. Commands can be sent to running instances, and commands can be stored and run in files. [ActiveX](http://realterm.sourceforge.net/index.html#ActiveX_Interface) and [Command Line](http://realterm.sourceforge.net/index.html#Command_Line_Parameters) commands are well documented. Sourceforge major releases are only made occasionally. To follow development versions see News and subscribe. -
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QModMaster
Modbus TCP,RTU Master Software.
QModMaster is a free, Qt-based Modbus master application. A graphical user interface provides easy communication with Modbus RTU and TCP slaves, and a built-in bus monitor lets you examine all traffic on the bus. QModMaster is based on libmodbus for protocol communication and QsLog for logging. It supports both Windows and Linux. For Windows, a pre-compiled binary is available — no installation required, just unzip and run. The repository has moved to GitHub https://github.com/elbarbas/QModMaster>. SourceForge will continue to host updated binary releases, but the latest source code is maintained on GitHub. Related project: pyModSlave http://sourceforge.net/projects/pymodslave — a Modbus slave for testing Video demos: https://www.youtube.com/channel/UC3Tk2gE-KGtwOq8WWmb2R7g -
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Vuze - Azureus
An extremely powerful and configurable BitTorrent client
Vuze (formerly Azureus) is an extremely powerful and configurable BitTorrent client. Search and download torrent files. Play, convert and transcode videos and music for playing on many devices such as PSP, TiVo, XBox, PS3, iTunes (iPhone, iPod, Apple TV). -
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Moodle
A free course management system (CMS) to create online learning sites
Moodle is a Course Management System (CMS), also known as a Learning Management System (LMS) or a Virtual Learning Environment (VLE). It is a Free web application that educators can use to create effective online learning sites. https://moodle.org/ -
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Outlook CalDav Synchronizer
Sync Outlook with Google, SOGo or any other CalDAV / CardDAV server
Free Outlook Plugin, which synchronizes events, tasks and contacts between Outlook and Google, SOGo, NextCloud, Horde or any other CalDAV or CardDAV server. Supported Outlook versions are 2021, 2019, 2016, 2013, 2010 and 2007 and Office 365 for Desktop. This project was initially developed as a master thesis project at the University of Applied Sciences Technikum Wien, Software Engineering Degree program. Outlook CalDav Synchronizer is Free and Open-Source Software (FOSS), still you can support the project by donating on Sourceforge or directly within the About dialog of our Plugin. Contact us for enterprise support at https://caldavsynchronizer.org/enterprise/contact -
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fldigi
Ham Radio Digital Modem Application
Fldigi is a modem program for most of the digital modes used by radio amateurs today: CW, PSK, MFSK, RTTY, Hell, DominoEX, Olivia, and Throb are all supported. It can help calibrate a sound card to a time signal and do frequency measurement tests. NOTICE: You must proceed to the Files section to locate the correct fldigi, flrig etal download for your particular operating system. Do not blithely use the big green Download button! Use the "Files" menu item or the "Browse All Files" link. -
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RATS Search
BitTorrent P2P multi-platform search engine for Desktop
Rats Search is a cross-platform search tool for torrent indexing across multiple BitTorrent DHT networks. It provides a GUI for searching decentralized torrent metadata in real time without relying on centralized indexes. Built with Electron and Vue.js, Rats Search emphasizes decentralization and anonymity, allowing users to explore content from distributed sources such as the BitTorrent Mainline DHT and WebTorrent. It supports filtering, magnet link generation, and acts as a privacy-conscious alternative to torrent search engines. -
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Universal G-Code Sender
A cross-platform G-Code sender for GRBL, Smoothieware, etc.
A full-featured gcode platform used for interfacing with advanced CNC controllers like GRBL , TinyG, g2core and Smoothieware. Universal Gcode Sender is a self-contained Java application that includes all external dependencies and can be used on most computers running Windows, MacOSX or Linux. With older versions of GRBL UGS is pretty reliable when it comes to jogging, but there are limitations. With GRBL 1.1 this is no longer the case when using the new JOG MODE syntax. This first-class jog mode guarantees the GCODE state will be unaltered and also allows you to stop a jog while it is in progress. UGS uses this new syntax automatically when it detects a version of GRBL which supports it. -
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Shareaza
A universal P2P file sharing client for Windows
Shareaza is a very powerful multi-network peer-to-peer file-sharing client supporting Gnutella² G2, Gnutella, eDonkey2000 / eMule, DC++, HTTP, FTP and BitTorrent / DHT protocols for Windows or Wine. -
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