UnicornScan

Unicornscan is a new information gathering and correlation engine built for and by members of the security research and testing communities. It was designed to provide an engine that is Scalable, Accurate, Flexible, and Efficient. It is released for the community to use under the terms of the GPL license.

BENEFITS
Unicornscan is an attempt at a User-land Distributed TCP/IP stack. It is intended to provide a researcher a superior interface for introducing a stimulus into and measuring a response from a TCP/IP enabled device or network. Although it currently has hundreds of individual features, a main set of abilities include:

• Asynchronous stateless TCP scanning with all variations of TCP Flags.
• Asynchronous stateless TCP banner grabbing.
• Asynchronous protocol specific UDP Scanning (sending enough of a signature to elicit a response).
• Active and Passive remote OS, application, and component identification by analyzing responses.
• PCAP file logging and filtering.
• Relational database output.
• Custom module support.
• Customized data-set views.

Get it from http://www.unicornscan.org/