Reading log4j and log4net logs. May be somewhat obsolete due to different logging solutions nowadays.
LogViewer for viewing and searching large text files...
Log Wizard - a Log Viewer that is easy and fun to use!
LogJoint log viewer core. Viewer plugins for publicly-available domains.
Sentinel is a log-viewer with configurable filtering and highlighting (foreground/background colours)
An advanced log viewer to use in WPF applications