Trafficmeter is a traffic collecting and logging system. It collects and groups packets by time, source IP, destination IP, protocol, source port, and destination port. You can get a detailed log of traffic for every IP without any daemon configuration work. It also gives statistics of IP incoming and outgoing traffic for a time period.
The XLog class can be used to write log messages to PHP or INI files. It can write details about events to log files that may include details such as event file, event line, event time and date, current page URL, and remote user IP address. The class can write to log files in either plain text format, INI format, or a PHP file that wraps the log messages in comments.
DenyThem is a program designed to protect your Linux system from malicious attacks. It is an active response system to disrupt and block dictionary attacks and DOS attacks. DenyThem by default uses /var/log/syslog and /var/log/auth.log and searches for hack attempts. When DenyThem finds enough hack attempts from a single host, it will add a DROP statement to your system's firewall, thus preventing future attacks. DenyThem uses iptables, so it will only work on Linux or any other system that uses iptables. It can also block traffic from specific countries.
Multiplexing Console Manager is a daemon that provides multiplexed access to network accessible consoles (e.g. terminal servers, Serial Over LAN, etc). Features include kerberized authentication, ACL based entitlements, multiple viewers/editors, full logging (simple text and timestamped, replayable XML) of all output.
Tweeter is another command line script that can update your Twitter status from the command line. It also uses the SSL link to protect your username and password. Tweeter can only post a new status; it cannot follow anyhone, send direct messages, or anything else. The username and password are not stored on the file system, so you can post to different accounts with ease. It should also work on older machines.
Seetxt is a lightweight text file and man page viewer for X windows. It maintains "document meta-data" for each user, allowing them to automatically keep bookmarks and highlights for read-only system files. It also has a "server mode" so that command line requests can be sent to a single running server rather than starting multiple instances. Other features include hypertext-style apropos (man page) searches, file monitoring, multi-level regular expression searching, a command history, and nice little toggle lights on the interface for the server and file monitor. There's also cross-application drag-n-drop support, and handy little features that allow you to view the output of shell commands and process the text buffer with an external command (sed, awk, grep, perl, etc.) Seetxt is POSIX compliant.
Lilith is a logging and access event viewer for the Logback logging framework. It has features comparable to Chainsaw, a logging event viewer for log4j. This means that it can receive logging events from remote applications using Logback as their logging backend. It uses files to buffer the received events locally, so it is possible to keep vast amounts of logging events at your fingertip while still being able to check only the ones you are really interested in by using filtering conditions.
Nagios is a host, service, and network monitoring system that will watch your network and alert you to problems before your clients or end-users do. The system runs checks on hosts and services that you specify using plugins that return status information to Nagios. When problems are encountered, the system will send notifications to system administrators so that they can take action on the problem. The JumpBox for Nagios gives you a head start to using the system. It eliminates the complexity involved in getting the application installed, and allows you to focus on the configuration for your specific environment. Since Nagios is based on plugins, depending on what you want to do this will vary in complexity.