Homedale allows you to monitor the signal strength of multiple WLAN Access Points.

OpenNetMeter enables simple network/data usage monitoring through an Open Source app.

CrystalDiskInfo Portable is an Open Source utility that monitors and displays the health of your hard drive, including basic information, S.M.A.R.T. values, and disk temperature. Also available as an installer.

Stats is an application that allows you to monitor your macOS system.

HWMonitor Portable is a straightforward hardware monitoring tool that delivers real-time statistics about the performance of your PC components. Installer version and Pro version download links are also available.

CrystalDiskInfo is an Open Source utility that monitors and displays the health of your hard drive, including basic information, S.M.A.R.T. values, and disk temperature. Also available as a portable version.

Libre Hardware Monitor is an Open Source fork of Open Hardware Monitor to monitor your computer's temperature sensors, fan speeds, voltages, load, and clock speeds.

HWMonitor is a free hardware monitoring program that reads PC systems' primary health sensors: voltages, temperatures, and fan speeds. Portable version via PortableApps is also available.

PRTG - Free Network Monitor is a network monitoring solution that ensures the availability of network components while also measuring traffic and usage.

SysGauge enables you to precisely monitor in real-time your machine's performance in numerous areas.

EF System Monitor gives you a well-rounded tool that can be used to retrieve a permanent record of information on all your network computers; these records include; memory space, hard disk usage, date, time, and username.

CPU Temp monitors CPU temperature, utilization, clock speed, power consumption, and other essential parameters in real time.

System Monitor (Sysmon) is a Windows system service and device driver that remains resident across system reboots to monitor and log system activity to the Windows event log.

DiskPulse gives you real-time monitoring of multiple disks and directories for unauthorized changes.

Advanced Host Monitor enables you to set up a customizable list of tasks and tests. It offers thorough monitoring options, allowing you to carefully check the network's performance and health.

Drives Monitor utilizes performance monitor data to visualize physical or logical disk activity.

FreeMeter is designed to monitor your system performance without using too many resources.

DU Meter monitors your computer's network bandwidth usage with real-time graphs, along with the ability to create reports and alerts based on your downloads and uploads.

RunCat for Windows is a portable app that illustrates CPU utilization via a running cat in the systray.

auto-cpufreq is a tool for Linux that can automatically optimize your computer's CPU speed and power consumption.

bottom (btm) is a cross-platform monitoring app.

LogFusion is a powerful log monitoring tool designed to allow for easy parsing of logs, including web server and developer debug logs.

Universal Radio Hacker (URH) is an Open Source app for investigating unknown wireless protocols.

LLDP-CDPMon allows you to capture and analyze LLDP/CDP packets that are transmitted over Ethernet connections.

Venmon is a robust real-time system resource monitoring utility that includes a multi-ping tool.