Open Source C++ Network Monitoring Software

Angry IP scanner is fast and friendly network scanner for Windows, Linux, and Mac. It is very extensible, allowing it to be used for very wide range of purposes, with the primary goal of being useful to network administrators.

Pandora OPEN is a high-performance, 100% open-source monitoring ecosystem, born as the independent evolution of the Pandora FMS community branch after version 777. Licensed under GPLv2, it provides a modular and sovereign platform for supervising networks, servers, and applications without commercial dependencies. It features multi-platform agents, remote monitoring (SNMP, WMI, HTTP), GIS maps, and advanced visual dashboards. Entirely maintained by the community on GitHub, it ensures total transparency, technical flexibility, and absolute freedom for system administrators.

VoIPmonitor is open source network packet sniffer with commercial frontend for SIP SKINNY MGCP RTP and RTCP VoIP protocols running on linux. VoIPmonitor is designed to analyze quality of VoIP call based on network parameters - delay variation and packet loss according to ITU-T G.107 E-model which predicts quality on MOS scale. Calls with all relevant statistics are saved to MySQL or ODBC database. Optionally each call can be saved to pcap file with either only SIP / SKINNY protocol or SIP/RTP/RTCP/T.38/udptl protocols. VoIPmonitor can also decode audio.

Visual Syslog Server for Windows is a free open source program to receive and view syslog messages. Useful when setting up routers and systems based on Unix/Linux. Visual Syslog Server for Windows has a live messages view: switches to a new received message. Helpful color highlighting. Useful message filtering. Customizable notification and actions. Sources hosted on the GitHub: https://github.com/MaxBelkov/visualsyslog

Conky is a free, light-weight system monitor for X, that displays any kind of information on your desktop. Conky is free software and runs in X on Linux and BSD. Originally a fork of Torsmo, Conky's torsmo-based code is BSD licensed. New code in Conky has been licensed under GPL 3.0. Since its inception, Conky has changed significantly from its predecessor, while maintaining simplicity and configurability. Conky can display just about anything, either on your root desktop, in its own window. Not only does Conky have many built-in objects, it can also display just about any piece of information by using scripts and other external programs. A plethora of OS stats (uname, uptime, CPU usage, mem usage, disk usage, "top" like process stats, and network monitoring, just to name a few). Conky can display information either as text, or using simple progress bars and graph widgets, with different fonts and colours.

SBLIM (pronounced "sublime"), the Standards Based Linux Instrumentation for Manageability is an IBM-initiated Open Source project, intended to enhance the manageability of GNU/Linux systems. It does so by enabling WBEM, Web Based Enterprise Management.

Zeek has a long history in the open source and digital security worlds. Vern Paxson began developing the project in the 1990s under the name “Bro” as a means to understand what was happening on his university and national laboratory networks. Vern and the project’s leadership team renamed Bro to Zeek in late 2018 to celebrate its expansion and continued development. Zeek is not an active security device, like a firewall or intrusion prevention system. Rather, Zeek sits on a “sensor,” a hardware, software, virtual, or cloud platform that quietly and unobtrusively observes network traffic. Zeek interprets what it sees and creates compact, high-fidelity transaction logs, file content, and fully customized output, suitable for manual review on disk or in a more analyst-friendly tool like a security and information event management (SIEM) system.