Nmap
Open Source
Nmap Free Security Scanner, Port Scanner, & Network Exploration Tool.
Angry IP Scanner
Open Source
IP scanner is a fast, friendly, extensible, free and open-source IP scanner to scan addresses and ports in any range.
Softperfect Network Scanner - NetScan
Commercial
SoftPerfect Network Scanner is a fast universal IPv4/IPv6 scanner with an extensive range of options and advanced features.
Zenmap
Open Source
Zenmap is the official cross-platform GUI for the Nmap Security Scanner. It is free and runs on Linux, Windows, Mac OS X, etc.
Advanced IP Scanner
Free
Advanced IP Scanner shows all network devices, gives you access to shared folders, and can even remotely switch computers off.
WinMTR
Open Source
WinMTR is a Windows application which combines the functionality of the traceroute and ping utilities in a single network diagnostic tool.
Compare Fing with alternatives
Compare Angry IP Scanner and Fing and decide which is most suitable for you.
Compare Advanced IP Scanner and Fing and decide which is most suitable for you.
Compare Softperfect Network Scanner - NetScan and Fing and decide which is most suitable for you.