syslog-ng is an enhanced log daemon, supporting a wide range of input and
output methods: syslog, unstructured text, message queues, databases (SQL
and NoSQL alike) and more.

Key features:

  * receive and send RFC3164 and RFC5424 style syslog messages
  * work with any kind of unstructured data
  * receive and send JSON formatted messages
  * classify and structure logs with builtin parsers (csv-parser(),
    db-parser(), ...)
  * normalize, crunch and process logs as they flow through the system
  * hand on messages for further processing using message queues (like
    AMQP), files or databases (like PostgreSQL or MongoDB).

The official home page of syslog-ng is:
http://www.balabit.com/network-security/syslog-ng/