Graylog

Splunk, the log analysis system that's evolved into a full-blown, machine-generated data processing platform (also described as "Google for visual analytics"), faces competition from a rising wave of open source competitors. One of the most prominent, Graylog, has unveiled its formal 1.0 release. Graylog's success won't be in meeting or exceeding Splunk's feature set or performance, though; it'll be in capturing or re-creating Splunk's existing ecosystem of users and applications.
via Infoworld