Snort is the IDS included with IPCop, and is one of the best-known and commonly used sniffers available today and used by networks large and small the world over. It has continually updated signatures for a massive number of vulnerabilities, a massive user base, commercial support, and excellent documentation available online as well as in print. Snort was initially developed by Martin Roesch in the late 1990's and was destined to be a sniffer and possibly a little more, hence the name Snort.
Initially as a sniffer Snort was quite good and was linked to its slightly older relative TCPDUMP. Eventually Snort was expanded and become known as more of a NIDS than a sniffer (many of Snort's users are unaware of its sniffing capabilities and use it purely as an IDS).
As Snort became very popular, Martin Roesch decided to start a company based on Snort to offer security services based on the expertise that he had as a Snort developer. This led to the creation of Sourcefire ...