Wikipedia
ntopng is computer software for monitoring traffic on a computer network. It is designed to be a high-performance, low-resource replacement for ntop. The name is derived from ntop next generation. ntopng is open-source software released under the GNU General Public License (GPLv3) for software. Source code versions are available for the operating systems: Unix, Linux, BSD, Mac OS X, and Windows. Binary versions are available for CentOS, Ubuntu, and OS X. A demo binary is available for Windows that limits analysis to 2,000 packets. ntopng's engine is written in the programming language C++. The optional web interface is written in Lua.
ntopng relies on the Redis key-value server rather than a traditional database, takes advantage of nDPI for protocol detection, supports geolocation of hosts, and is able to display real-time flow analysis for connected hosts.