Rsyslog is an enhanced syslogd supporting, among others, MySQL, PostgreSQL, failover log destinations, syslog/tcp, fine grain output format control, high precision timestamps, queued operations and the ability to filter on any message part.
NXLog provides a broad range of features for collecting, processing, forwarding, and storing log data. In concept it is similar to syslog-ng or rsyslog, but it is not limited to Unix-like services only.
Nagios Log Server is a powerful enterprise-class log monitoring and management application that allows organizations to quickly and easily view, sort, and configure logs from any source on any given network.
Mac-OSX Syslog Center is syslog server monitor and analyzer software for syslog events and notifications that supports any vendor and helps to monitor, analyze, report and correlate real-time network events.
Syslog Watcher installs a dedicated syslog server, integrating log data from multiple network devices into a single, easily manageable and accessible place. Collecting and analyzing syslogs is essential for maintaining network stability and auditing network security.
The Snare Server, from InterSect Alliance, is a proprietary Log Monitoring solution that builds on the open source Snare agents to provide a central audit event collection, analysis, reporting and archival system.