A new freeware version of Netwitness' core product, NetWitness Investigator, was made available today.  I was able to get access to it several days ago for a test run.  It looks and feels much like Wireshark, but with a lot more capability.  The only two issues I found with the tool is that the registration process (required) is a bit quirky but eventually works, and you'll see a noticible drop in computer performance while its running.  But considering that this is a sniffer on steroids I suspect that a performance drop is to be expected. 

Here are notes from the NetWitness web site:

Product Features:

• Captures raw packets live from most wired or wireless interfaces
• Imports packets from any open-source, home-grown and commercial packet capture system (e.g. .pcap file import)
• License supports 25 simultaneous 1GB captures - far exceeding data manipulation capabilities of packet tools like Wireshark
• Real-time, patented layer 7 analytics
       – Effectively analyze data starting from application layer entities like users, email, address, files , and actions.
       – Infinite, free-form analysis paths
       – Content starting points
       – Patented port agnostic service identification
• Extensive network and application layer filtering (e.g. MAC, IP, User, Keywords, Etc.)
• IPv6 support
• Full content search, with Regex support
• Exports data in .pcap format
• Bookmarking & history tracking
• Integrated GeoIP for resolving IP addresses to city/county, supporting Google® Earth visualization
• NEW! SSL Decryption (with server certificate)
• NEW! Interactive time charts, and summary view
• NEW! Interactive packet view and decode
• NEW! Hash PCAP on Export
• NEW! Enhanced content views

Minimum system requirements:
NetWitness recommends the following minimum hardware requirements for NetWitness Investigator:

• Windows® XP, 2003 Server, or Vista 32-bit
• Single 2Ghz Intel-based processor(Dual-core recommended)
• 1GB RAM(2GB Recommended)
• 1 Ethernet Port
• Internet Explorer v7+ (IE v6.x may limit some functionality)
• Ample data storage for collected data
• Note: Linux infrastructure available in commercial versions

The fully functional and licensed free version of NetWitness Investigator is at: http://download.netwitness.com.  We are interested in your comments if you've downloaded and tried this software.  Please let us know via our contact form.

Marcus H. Sachs
Director, SANS Internet Storm Center