nxlog - NXLog offers log management solutions for companies of all sizes.
Wazuh - Open Source Host and Endpoint Security
Kiwi Syslog Server - Kiwi Syslog Server prvides solution to centralize and simplify log message management across network devices and servers.
Beats - Beats is the platform for single-purpose data shippers that is installed as lightweight agents and send data to machines to Logstash or Elasticsearch.
rsyslog - Rsyslog is an enhanced syslogd supporting, among others, MySQL, PostgreSQL, failover log...
Graylog - Graylog is an open source log management platform for collecting, indexing, and analyzing both structured and unstructured data.