NewSyslog is an updated version of a package put together by Theodore Tso of MIT Project Athena (which is included in NetBSD, FreeBSD, OpenBSD, etc.). It manages the rotation and archiving of log files (primarily those written to by syslogd). This version has a mix of features from all of the other versions, and it has been made more portable than any of the others with the help of GNU Autoconf.
pflogsumm.pl is designed to provide an over-view of postfix activity, with just enough detail to give the administrator a "heads up" for potential trouble spots. Reports includes: Total number of messages and bytes; Hosts/Domains; senders and Recipients; per-hour traffic reports; summaries of warnings, fatal errors, and panics; and so on ...
Secure Syslog is a cryptographically secure system logging tool for UNIX systems. Designed to replace the syslog daemon, ssyslog implements a cryptographic protocol called PEO-1 that allows the remote auditing of system logs. Auditing remains possible even if an intruder gains superuser privileges in the system, the protocol guarantees that the information logged before and during the intrusion process cannot be modified without the auditor (on a remote, trusted host) noticing.
Installwatch is a simple utility which keeps track of which files are created and modified during the installation of a new program. It's fast and easy to use. It doesn't require a "pre-install" phase because it monitors processes while they run. Installwatch works with every dynamically linked ELF program, by intercepting system calls that cause file system alterations.
httplog is a replacement for Apache's 'rotatelogs' and Andrew Ford's 'chronolog'. It allows you to specify a logfile using strftime paramaters in the filename to act as a template. This means that the logs in your logfiles will also be sorted according to the filename. For example, if you specify a logfile of /var/log/http%Y%m%d.log, a new log file would be generated each day, with content for only that one day. It also supports compression of logfiles using gzip, and many other useful functions.