Angry IP Scanner

From Angryziber Software:

Angry IP scanner is a very fast IP scanner for Windows. It can scan IPs in any range. Its binary file size is very small compared to other IP scanners. Angry IP scanner simply pings each IP address to check if it's alive, then optionally it is resolving hostname, scans ports.

It also has additional features like NetBIOS information (computer name, workgroup name, currently logged in user and MAC address), results saving to CSV, TXT, HTML or XML file, can be used as a command-line utility in a batch file, etc. With help of plugins, Angry IP Scanner can gather any information about scanned IPs. Anybody who can write code is able to write plugins and extend functionality of Angry IP Scanner.