Nmap - Nmap Free Security Scanner, Port Scanner, & Network Exploration Tool. Download open source software for Linux, Windows, UNIX, FreeBSD, etc.
Zerto - Virtual replication & recovery solution
Angry IP Scanner - Open-source and cross-platform network scanner designed to be fast and simple to use
INAP Bare Metal - INAP Bare Metal is an intelligent monitoring service for bare metal dedicated and virtual servers.
Advanced IP Scanner - Advanced IP Scanner shows all network devices, gives you access to shared folders, and can even remotely switch computers off. Download it Free.
Barracuda MSP - Barracuda MSP is the first and only MSP-focused provider of advanced threat protection with backup & disaster recovery - complete data protection for MSPs.