SpamTitan

SpamTitan is "the most comprehensive solution to email threats on the market today". I have implemented this solution to provide "protection from Viruses, Spam, Malware, Phishing and unwanted content" and it works very well. I used the VMware virtual machine image and converted it to run on ESX server.

• The interface is very impressive and setup was quite straight forward - no reading of the manual required.
• Uses two anti-virus engines: Kaspersky and ClamAV
• Uses OCR to detect image-spam
• Multi-layer anti-spam approach - scoring from several algorithms is compiled to provide a single spam score.
  
• The product checks for valid recipients (including aliases) against my Exchange server.
• Logging and reporting are excellent.
• There have been some false positives and initially it didn't block as much spam as I had hoped but as the Beyesian analysis has improved so have the detection rates.
• I have been monitoring the quarantine and whitelisting the domains from which we often see mail.
  
• I am not yet sending outgoing mail through my SpamTitan but this should improve the filters as well.
• After an upgrade, the ClamAV definitions were no longer being updated. I contacted support and they connected from remote (via a tunnel I opened) and fixed the problem. An excellent support experience.

I was surprised to find that in the two weeks or so that I have been filtering my SMTP traffic that we are averaging only approximately 20% legitimate mail.

NASLite-2 CDD

"NASLite-2 CDD is a Network Attached Storage (NAS) Server Operating System designed to transform a basic computer into a dedicated SMB/CIFS, NFS, FTP, HTTP and RSYNC file server. NASLite-2 CDD is specifically designed to boot directly from a CD-ROM and is intended for use in any low-security environment or application that requires the simultaneous availability of large amounts of inexpensive networked storage. A single NASLite-2 CDD server is capable of exporting terabytes of networked storage and is capable of handling 50 or more networked users easily and efficiently even when running on modest hardware. By design, NASLite-2 CDD is a community workgroup server and does not support features such as user management, disk quotas or the ability to join domains. However, it is very easy to set-up, to administer and to use."

Not free but inexpensive and looks quite slick. Also consider FreeNAS.

Iperf - Bandwidth Testing Tool

Iperf is "a tool to measure maximum TCP bandwidth, allowing the tuning of various parameters and UDP characteristics. Iperf reports bandwidth, delay jitter, datagram loss."

This is an interesting tool used to test network throughput. I stumbled across it in an Ars Technica Forum thread.

The recommended syntax and options (from the Ars thread):
server: iperf -s
client: iperf -c server -l 64k -t 15 -i 3 -r

Wireshark

"Wireshark is a network protocol analyzer for UNIX, OS X and Windows. It allows you to examine data from a live network or from a capture file on disk. You can interactively browse the capture data, viewing summary and detail information for each packet." It's a packet sniffer.

Formerly known as 'Ethereal'. Project Page.

Scorched3D

Remember Scorched Earth? The wonderful and addictive little DOS-based game where two players operating tanks lob artillery shells (etc.) at each other?

Well, I stumbled accross the SourceForge Project of the Month for May, 2007, Scorched3D:

"Scorched3D is a 3D remake of the popular 2D artillery game Scorched Earth.
Scorched3D can be played against the computer, other players and remotely across
the Internet or LAN."

Here are links to the project page and official web site.