iplog is a TCP/IP traffic logger. Currently, it is capable of logging TCP, UDP, and ICMP traffic. iplog is able to detect TCP port scans, TCP null scans, FIN scans, UDP and ICMP "smurf" attacks, bogus TCP flags, TCP SYN scans, TCP "Xmas" scans, ICMP ping floods, UDP scans, and IP fragment attacks. iplog is able to run in promiscuous mode and monitor traffic to all hosts on a network. iplog uses libpcap to read data from the network and can be ported to any system that supports pthreads and on which libpcap will function.
Isoqlog is an MTA log analysis program written in C. It is designed to scan qmail, Postfix, Sendmail, and Exim logfiles and produce usage statistics in HTML for viewing through a browser. It produces a "top domains" statistic according to sender, receiver, total mails, and bytes, and keeps the main domain mail statistics with regard to day's top domain, and top users values for per day, per month, and per year.
PIKT is cross-categorical, multi-purpose software for monitoring and configuring computer systems, administering networks, organizing system security, and much more. PIKT is intended primarily for system monitoring, and secondarily for configuration management, but its versatility and extensibility evoke many other wide-ranging uses. PIKT consists of a sophisticated, feature-rich file preprocessor; an innovative scripting language with unique labor-saving features; a flexible, centrally directed process scheduler; a customizing file installer; a collection of powerful command-line extensions; and other useful tools.
syslog-ng is a syslogd replacement for a wide variety of UNIX systems that supports IPv6 and is capable of transferring log messages reliably using TCP and SSL and filtering the content of messages using regular expressions. Both RFC3164 and RFC5424 style messages are handled, but more esoteric formats like BSD process accounting logs are supported too. Apart from regular text files, it supports storing messages into SQL and MongoDB databases, and forward messages to local processes via pipes or UNIX domain sockets. This makes syslog-ng ideal as an integration platform. syslog-ng supports extracting structured information from the traditionally text based syslog via csv-parser(), db-parser(), and patterndb. Tag based classification, rewriting messages, and outputting messages in JSON is also possible. This makes syslog-ng ideal for preprocessing events for further analysis, be that home-grown scripts or SIEM systems. syslog-ng scales well on today's multi processor and multi-core systems: reaching 1,000,000 messages per second is a reality for the simplest use cases.
SysOrb is a client/server package that can monitor servers remotely (such as Web servers), or monitor devices on servers (such as disks, memory, load, etc.). It will alert the administrators via e-mail or pager if a server is entering a critical condition, and has its own database backend, allowing for massive collection of system statistics.
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.