So, What Is Snort?
Snort is an Open Source, lightweight Network Intrusion Detection System licensed under the GNU Public License (GPL) and written primarily by Martin Roesch in 1998. If you are unfamiliar with the term Open Source and the implications thereof, please read the Open Source Definition on the Open Source Initiative's Web site (http://www.opensource.org/). For more information about the GPL, please visit the GNU Project's Web site (http://www.gnu.org/).
Since the initial release of Snort, it has grown in popularity, and has a very active user and developer community supporting it directly or indirectly through mailing lists or add-on software utilities. In 2000, an important milestone was reached when Michael Davis ported Snort to the Win32 platform, bringing parity to those running Windows NT or 2000.
Installing and configuring Snort is not for the faint-of-heart. There are no pointy, clicky, GUI-type installers or automagic configuration utilities. Installation and configuration requires access and extensive use of the command-line. Snort is neither difficult to configure nor difficult to use; it just takes a little learning on your part. And, truthfully, if you aren't willing to invest a little time in knowing what your network is doing and how it is being secured, you're not keeping your network secure.