libKISSlog is a trivial lightweight C++ template library designed and written according to the KISS (Keep It Simple and Straightforward) principle. It leans heavily on STL for keeping its implementation as simple as its usage, and tries to provide C++ developers with a lightweight, paradigm-pure, and flexible alternative to logging libraries which use design and/or implementation decisions which at least the author of libKISSlog believes to be questionable. Its easiest to explain why libKISSlog would be suitable for your needs by listing the things which libKISSlog does not choose to use or do: no singletons or other forms of mutable global state, no macros, no attempt to fit the Java runtime everything model onto a C++ library, no attempt to be a Java-style (bloated) framework, no attempt to make the choice for you of whether you need thread safety, and no compromise on simplicity in order to facilitate questionable inner-loop logging practices.
Ipt_fw is a firewall for Linux based on iptables. It is designed for client systems. Ipt_fw outputs a shell script containing iptables commands, so inspection of the settings it creates is easy. The configuration files are made in LibreOffice（OpenOffice）Calc. Making of the firewall and a machine using the firewall are separated. It allows you to set the user level and features detailed logging, IP address blacklist management, and iptables integrity.
pam_ttylog is a PAM module to log console output of a login shell. pam_ttylog takes an approach that makes a script-like environment in the PAM session section of /bin/login. Thus, the log files are in a user-unreachable directory and have user-unreadable/unwritable permissions. As PAM module, it doesn't need to modify or replace the original /bin/login, getty, telnet, or libraries for its installation and operation.
liblognorm is a tool to normalize log data. It takes logs in different formats as input and outputs the data within them in a single, consistent format. For example, if you have traffic logs from three different firewalls, liblognorm will be able to normalize all the events into a generic form. Among other features, it can extract source and destination IP addresses and ports and make them available via well-defined fields. The result is that a common log analysis application will be able to work on that common set independently from the actual firewalls feeding it. Even better, once a well-understood interim format exists, it is also easy to convert that into any other vendor specific format, so that you can use that vendor's analysis tool.
ColorLogs is an output-colorizing Perl script intended to have command output piped through it to a terminal. It allows easy creation of new highlighting configurations using simple text matches, globs, or regular expressions. It works transparently even in interactive contexts with scripts that produce prompt lines and wait for user input. Patterns are provided for Ant and Maven output. This version started as a fork of v1.1 from resentment.org, but numerous improvements have been made since then.
pdr (personal data recorder) and pdx (personal data expert) are applications that collect and evaluate mostly numeric personal data. The intended use case is for logging individual medical data (blood sugar, blood pressure, body temperature, weight, heart rate, and medications), but they can also be used for technical, sports, fitness, weather, environmental, or financial data. They work on a continuous flow of numbers in time that you want to monitor. Every data item can also be commented by text. pdr can use Twitter and email accounts for data input, which makes mobile phones usable for data input. It is one of the few free applications for diabetics.