Zeek (Bro) is an open source intrusion detection system (IDS).
It is different from traditional IDS tools in that it is
focused on network analysis. In other words, it is used
to monitor traffic traversing a network to identify anomalies.

This is the last version of zeek supported by GCC v5.5.0

Zeek v3.1.0 and newer requires GCC v7 for C++17 support.