Iptqlog is the IPTables Queue LOGger. It produces clean, easy-to-understand, and (optionally) colorized logs of the packets that were sent to the user space using the QUEUE target in iptables. Its key features are resolving of IP numbers, port numbers, and protocol numbers, logging to standard output, syslog, or both, saving packets in pcap dump format and the ability to create your own output format.
Node Runner is a network monitor which is designed to contact network nodes in a specific order based on the hierarchy of your network. If a node does not respond, each of its parents are systematically checked until the true problem is identified. Node Runner uses a shell script for its network polling, a Web interface for node information, reports, etc., and utilizes abstraction layers for database support.
Trace.java is a package used by Java programmers, testers, server administrators and others to understand what happened during the execution of a program. It doesn't generate tracing statements automatically; programmers have to add them. Trace messages go into an in-core ring buffer, a disk log, or both. The disk log can be fixed size with backups. What amount of detail gets logged can be controlled at runtime or launch time. The ring buffer and disk log can be controlled separately. Different subsystems of the code can be controlled independently.
logn (login-notifier) notifies you about logins of other users. It uses the file /var/log/wtmp for this task and scans this file for login of users. When someone logs in (e.g., using ssh, telnet or FTP) an informational line about the login is printed on your console. To ease idling around on a remote machine with firewall/NAT between you and the remote machine, logn outputs an ASCII NUL character every 8 minutes.
Chainsaw is a GUI log viewer and filter for the Log4J package. It listens for LoggingEvent objects sent using the SocketAppender and displays them in a table. The events can be filtered based on Priority, Thread name, Category name, or Message. It can also load events logged to a file.
glogwatch is a GKrellM plugin that alllows the monitoring of an arbitrary file, such as /var/log/messages, or a SNORT alert file, for changes. Once a change is detected, a timer is displayed showing the elapsed time since the change occurred. The timer is reset and re-armed when the user clicks on the plugin to view the file.