syslog-ng

syslog-ng is a free and open-source implementation of the syslog protocol for Unix and Unix-like systems. It extends the original syslogd model with content-based filtering, rich filtering capabilities, flexible configuration options and adds important features to syslog, like using TCP for transport. As of today, syslog-ng is developed by Balabit IT Security Ltd. It has three editions with a common codebase. The first is called syslog-ng Open Source Edition with the license LGPL. The second is called Premium Edition and has additional plugins under a proprietary license. The third is called Storebox, which comes as an appliance with a Web-based UI as well as additional features including ultra-fast-text search, unified search, content-based alerting and a premier tier support.