TCPWebLog is a system that collects and aggregates Apache and Varnish Web server logs from multiple Linux computers. It uses a simple "client" program that pipes logs to a central server over a TCP connection, and a "server" program that receive the logs and quickly aggregates or splits them.
zlog is a reliable, efficient, thread safe, flexible, pure C logging library. It was written because there were no good C logging libraries along the lines of Logback for Java or log4cxx for C++. printf can work, but can not be easily redirected or reformatted, and syslog is slow and designed for system use. It provides a syslog model, log format customization, multiple output, safe run-time reconfiguration, high performance, user-defined log levels, safe log rotation, a log4j-style key-value map, in-built debugging, and no external dependencies.
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.
Callstats collects and displays call statistics for Siemens HiPath OpenOffice ME in a pretty Web interface. It may work with other Siemens HiPath devices (probably Hipath 3000). With some modifications, it could be adapted to your own system. It has 3 parts: -tcp->text log (via netlog); text log->sqlite database (PHP script); and a Web interface to the SQLite database (PHP). It has been tested without problems in a 50-user installation fulltime since 2009.
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.
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.