Total Network Inventory: Professional PC audit and network inventory management software - fits best for a for companies of all sizes. Free for 60 days.
DCImanager is a platform for managing physical equipment, which helps to optimize the use of computing power, improve the efficiency of the IT department, and flexibly transform the infrastructure according to business tasks.
In a single web interface, the system allows you to keep an inventory of equipment and monitor the occupancy of racks. The system also allows for remotely managing servers and power supply, configuring of networks, quickly restoring the infrastructure after failures, and monitoring the load on equipment. DCImanager is compatible with the most popular vendors' equipment.
Network Inventory Advisor - Network Inventory Advisor audits all network software and hardware simply and efficiently
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Lansweeper - Lansweeper discovers Windows, Linux and Mac machines in your network.
Opendcim - a free, web based Data Center Infrastructure Management application.
Nmap - Nmap Free Security Scanner, Port Scanner, & Network Exploration Tool. Download open source software for Linux, Windows, UNIX, FreeBSD, etc.
Device42 - Automatically maintain an up-to-date inventory of your physical, virtual, and cloud servers and containers, network components, software/services/applications, and their inter-relationships and inter-dependencies.