Free network-related software

daemon and utilities for an anonymizing network

BIND () is a suite of software for interacting with the Domain Name System (DNS). Its most prominent component, named (pronounced name-dee: , short for name daemon), performs both of the main DNS server roles, acting as an authoritative name server for DNS zones and as a recursive resolver in the network. As of 2015, it is the most widely used domain name server software, and is the de facto standard on Unix-like operating systems. Also contained in the suite are various administration tools such as nsupdate and dig, and a DNS resolver interface library.

The Invisible Internet Project (I2P) is an anonymous network layer (implemented as a mix network) that allows for censorship-resistant, peer-to-peer communication. Anonymous connections are achieved by encrypting the user's traffic (by using end-to-end encryption), and sending it through a volunteer-run network of roughly 55,000 computers distributed around the world. Given the high number of possible paths the traffic can transit, a third party watching a full connection is unlikely. The software that implements this layer is called an "I2P router", and a computer running I2P is called an "I2

OpenSSH (also known as OpenBSD Secure Shell) is a suite of secure networking utilities based on the Secure Shell (SSH) protocol, which provides a secure channel over an unsecured network in a client–server architecture.

thumb|Virtual Network Computing logo thumb|VNC in KDE 3.1

rsync (remote sync) is a utility for transferring and synchronizing files between a computer and a storage drive and across networked computers by comparing the modification times and sizes of files. It is commonly found on Unix-like operating systems and is under the GPL-3.0-or-later license.

content-addressable, peer-to-peer hypermedia distribution protocol

D-Bus (short for "Desktop Bus"

Psiphon is a free and open-source Internet censorship circumvention tool that uses a combination of secure communication and obfuscation technologies, such as a VPN, SSH, and a Web proxy. Psiphon is a centrally managed and geographically diverse network of thousands of proxy servers, using a performance-oriented, single- and multi-hop routing architecture.

Netfilter is a framework provided by the Linux kernel that allows various networking-related operations to be implemented in the form of customized handlers. Netfilter offers various functions and operations for packet filtering, network address translation, and port translation, which provide the functionality required for directing packets through a network and prohibiting packets from reaching sensitive locations within a network.

NetworkManager is a daemon that sits on top of libudev and other Linux kernel interfaces (and a couple of other daemons) and provides a high-level interface for the configuration of the network interfaces to simplify the use of computer networks on Linux distributions.

zero-configuration networking (zeroconf) implementation

ZeroNet is a decentralized web-like network of peer-to-peer users, created by Tamas Kocsis in 2015. The programming for the network was based in Budapest, Hungary. It is built in Python and fully open source. Instead of having an IP address, sites are identified by a public key (specifically a bitcoin address). The private key allows the owner of a site to sign and publish changes, which propagate through the network. Sites can be accessed through an ordinary web browser when using the ZeroNet application, which acts as a local webhost for such pages. In addition to using bitcoin cryptography,

rdesktop is an implementation of a client software for Microsoft's proprietary Remote Desktop Protocol (RDP). Rdesktop is free and open-source software, subject to the requirements of the GNU General Public License (GPL-3.0-or-later), and is available for Linux and BSD as well as for Microsoft Windows.

network administration command-line tool

Privoxy is a free non-caching web proxy with filtering capabilities for enhancing privacy, manipulating cookies and modifying web page data and HTTP headers before the page is rendered by the browser. Privoxy is a "privacy enhancing proxy", filtering web pages and removing advertisements. Privoxy can be customized by users, for both stand-alone systems and multi-user networks. Privoxy can be chained to other proxies and is frequently used in combination with Squid among others and can be used to bypass Internet censorship.

load balancing software

simplified netfilter interface

TightVNC is a free and open-source remote desktop software server and client application for Linux and Windows. A server for macOS is available under a commercial source code license only, without SDK or binary version provided. Constantin Kaplinsky developed TightVNC, using and extending the RFB protocol of Virtual Network Computing (VNC) to allow end-users to control another computer's screen remotely.

dnsmasq is free software providing Domain Name System (DNS) caching, a Dynamic Host Configuration Protocol (DHCP) server, router advertisement and network boot features, intended for small computer networks.

event-driven network programming framework

Unix program for DNS lookups

Fail2Ban is an intrusion prevention software framework. Written in the Python programming language, it is designed to prevent brute-force attacks. It is able to run on POSIX systems that have an interface to a packet-control system or firewall installed locally, such as iptables or TCP Wrapper.

web decentralization project

Scapy is a packet manipulation tool for computer networks, originally written in Python by Philippe Biondi. It can forge or decode packets, send them on the wire, capture them, and match requests and replies. It can also handle tasks like scanning, tracerouting, probing, unit tests, attacks, and network discovery.

Linux IP Firewalling Chains, normally called ipchains, is free software to control the packet filter or firewall capabilities in the 2.2 series of Linux kernels. It superseded ipfirewall (managed by ipfwadm command), but was replaced by iptables in the 2.4 series. Unlike iptables, ipchains is stateless.

In Internet computing, NSD (for "name server daemon") is an open-source Domain Name System (DNS) server. It was developed by NLnet Labs of Amsterdam in cooperation with the RIPE NCC, from scratch as an authoritative name server (i.e., not implementing the recursive caching function by design). The intention of this development is to add variance to the "gene pool" of DNS implementations used by higher level name servers and thus increase the resilience of DNS against software flaws or exploits.

JXTA (Juxtapose) was an open-source peer-to-peer protocol specification begun by Sun Microsystems in 2001. The JXTA protocols were defined as a set of XML messages which allow any device connected to a network to exchange messages and collaborate independently of the underlying network topology.

UltraVNC (sometimes written uVNC) is an open-source remote-administration/remote-desktop-software utility.

GLPI (acronym: , or "Free IT Equipment Manager" in English) is an open source IT Asset Management, issue tracking system and service desk system. This software is written in PHP and distributed as open-source software under the GNU General Public License.

hping is an open-source packet generator and analyzer for the TCP/IP protocol created by Salvatore Sanfilippo (also known as Antirez). It is one of the common tools used for security auditing and testing of firewalls and networks, and was used to exploit the idle scan scanning technique (also invented by the hping author), and now implemented in the Nmap Security Scanner. The new version of hping, hping3, is scriptable using the Tcl language and implements an engine for string based, human-readable description of TCP/IP packets so that the programmer can write scripts related to low level TCP/

real-time communication software framework

thumb|right|300px|An example of the default DansGuardian blocking message.

Wicd, which stands for Wireless Interface Connection Daemon, is an open-source software utility to manage both wireless and wired networks for Linux. The project started in late 2006 with the creation of Connection Manager, which eventually became Wicd. Wicd aims to provide a simple interface to connect to networks with a wide variety of settings.

OpenAFS is an open-source implementation of the Andrew distributed file system (AFS). AFS was originally developed at Carnegie Mellon University, and developed as a commercial product by the Transarc Corporation, which was subsequently acquired by IBM. At LinuxWorld on 15 August 2000, IBM announced their plans to release a version of their commercial AFS product under the IBM Public License. This became OpenAFS. Today, OpenAFS is actively developed for a wide range of operating system families including: AIX, Mac OS X, Darwin, HP-UX, Irix, Solaris, Linux, Microsoft Windows, FreeBSD, NetBSD.

DNS server

alternative SSH-server and client

PowerDNS is a software project providing a DNS authoritative server, recursor and proxy. It is written in C++ and licensed under the GPL. It runs on most Unix derivatives. PowerDNS features a large number of different backends ranging from simple BIND style zonefiles to relational databases and load balancing/failover algorithms.

WebTorrent is a peer-to-peer (P2P) streaming torrent client written in JavaScript that enables BitTorrent functionality directly within web browsers. Created by Feross Aboukhadijeh, the developer behind YouTube Instant, WebTorrent implements the BitTorrent protocol using WebRTC for peer-to-peer data transfer, allowing users to download and stream torrents without requiring traditional torrent client software.

software for monitoring computer networks

Internet censorship circumvention software

daemon which implements the PPP protocol for internetworking over dialup lines

open source security software

software library for HTTP connection in Python

Rclone is an open source, multi threaded, command line computer program to manage or migrate content on cloud and other high latency storage. Its capabilities include sync, transfer, crypt, cache, union, compress and mount. The rclone website lists supported backends including S3 and Google Drive.

WvDial (pronounced 'weave-dial') is a utility that helps in making modem-based connections to the Internet that is included in some Linux distributions. WvDial is a Point-to-Point Protocol dialer: it dials a modem and starts pppd in order to connect to the Internet. It uses the wvstreams library.

Opentracker is a free (licensed as beerware) BitTorrent peer tracker software (a special kind of HTTP or UDP server software) that is designed to be fast and to have a low consumption of system resources.

OSSEC (Open Source HIDS SECurity) is a free, open-source host-based intrusion detection system (HIDS). It performs log analysis, integrity checking, Windows registry monitoring, rootkit detection, time-based alerting, and active response. It provides intrusion detection for most operating systems, including Linux, OpenBSD, FreeBSD, OS X, Solaris and Windows. OSSEC has a centralized, cross-platform architecture allowing multiple systems to be easily monitored and managed. OSSEC has a log analysis engine that is able to correlate and analyze logs from multiple devices and formats.

network diagnostic software

software

iPXE is an open-source implementation of the Preboot eXecution Environment (PXE) client software and bootloader, created in 2010 as a fork of gPXE (gPXE was named Etherboot until 2008). It can be used to enable computers without built-in PXE capability to boot from the network, or to provide additional features beyond what built-in PXE provides.

Vinagre is a discontinued VNC, SSH, RDP and SPICE client for the GNOME desktop environment, superseded by GNOME Connections. Vinagre was included in GNOME 2.22. It has several features, like the ability to connect to multiple servers simultaneously and to switch between them using tabs, VNC servers browsing and bookmarking. In version 2.29, Vinagre added controlling frame compression, better scaling and color depth. Version 2.30 added improved SSH tunneling and better support for copy-paste features between client and server.

open source service-to-service portability platform

The Router Advertisement Daemon (radvd) is an open-source software product that implements link-local advertisements of IPv6 router addresses and IPv6 routing prefixes using the Neighbor Discovery Protocol (NDP) as specified in .

EtherApe is a packet sniffer/network traffic monitoring tool, developed for Unix. EtherApe is free, open source software developed under the GNU General Public License.

tool for exchanging contents in an anonymous and secure way over a friend-to-friend (F2F) network

GoodbyeDPI is a free and open-source software tool for bypassing deep packet inspection (DPI) systems and Internet censorship. It was created by Russian developer ValdikSS in 2016 and is distributed under the Apache License via GitHub.