Angry IP Scanner : IP address and port scanner
Angry IP Scanner is a small open source Java application which performs host discovery (“ping scan”) and port scans. The old 2.x release was Windows-only, but the new 3.X series runs on Linux, Mac, or Windows as long as Java is installed. Version 3.X omits the vampire zebra logo. As with all connect()-based scanners, performance on Windows XP SP2 and Vista can be poor due to limitations added to tcpip.sys. The Angry FAQ provides details and workarounds. A short review was posted to nmap-dev.