PRTG is a network monitoring tool that helps you to ensure that your computer systems are running smoothly and that no outages occur. Developed by Paessler AG
License: Freemium
Cacti is a powerful open-source network monitoring tool that excels in long-term data collection and customization, but has a steeper learning curve. In contrast, PRTG Network Monitor offers a more user-friendly experience with real-time monitoring capabilities and built-in reporting, but comes with a licensing cost.