From Lizard Systems:
Network scanner is an IP scanner for network analysis that will allow you to see all network computers in several seconds. It can scan an unlimited number of IP address ranges or computers from a list. It scans computers not only for NetBIOS resources, but also for running FTP and web services. It is possible to check access right to resources during the scan process. Network scanner works really fast due to multi-thread scanning when every computer is scanned independently. You can change the number of computers scanned simultaneously. You can export the scan results to html, txt or xml.