Wazuh - Open Source Host and Endpoint Security

Datadog - See metrics from all of your apps, tools & services in one place with Datadog's cloud monitoring as a service solution. Try it for free.

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.

Heka - heka - Data collection and processing made easy.

Syslog-ng - Syslog-ng decreases the quantity and improves the quality of data, thus enhancing the capacities of your SIEM solution.

logstash - logstash is a tool for managing events and logs.