NSAT is a robust scanner which is designed for:

* Different kinds of wide-ranging scans, keeping stable for days
* Scanning on multi-user boxes (local stealth and non-priority scanning options)
* Professional-grade penetration testing and comprehensive auditing
* Easy full-scale archiving of vulnerability and version information for further purposes
* Time-less configuration - as a banner scanner for many known services and protocols
* Virtual host support, host/network exclusion support
* Flexibility and configurable scanning
* Distributed scanning (new feature; beta status)

Works on:
All BSD Platforms (FreeBSD/NetBSD/OpenBSD/Apple Mac OS X),
All POSIX (Linux/BSD/UNIX-like OSes),
Linux, Solaris