Fluentd - Fluentd is a cross platform open source data collection solution originally developed at Treasure Data.
Kiwi Syslog Server - Kiwi Syslog Server prvides solution to centralize and simplify log message management across network devices and servers.
logstash - logstash is a tool for managing events and logs.
Graylog - Graylog is an open source log management platform for collecting, indexing, and analyzing both structured and unstructured data.
Wazuh - Open Source Host and Endpoint Security
Splunk - Splunk's operational intelligence platform helps unearth intelligent insights from machine data.