Snort is #3 in Top 10 Intrusion Detection Systems

https://www.snort.org/
Snort
Snort is the foremost Open Source Intrusion Prevention System (IPS) in the world. Snort IPS uses a series of rules that help define malicious network activity and uses those rules to find packets that match against them and generates alerts for users.

Positions in ratings


#3 in Top 10 Intrusion Detection Systems

Alternatives


The best alternatives to Snort are: OSSEC, Suricata, Zeek, Wireshark, pfSense, Security Onion
See also:
Top 10 Intrusion Detection Systems