Anteater is a log analyser for MTA logfiles (such as those produced by sendmail and postfix). The tool is written in 100% C++ and is very easy to customize. Input, output, and the analysis are modular class objects with a clear interface. Currently, there are modules for reading the syslog format of sendmail and postfix that do up to eight useful analyses and write the result in plain ASCII or HTML, to stdout or to files.
DansGuardian is a Web content filtering proxy that uses Squid to do all the fetching. It filters using multiple methods including, but not limited to, phrase matching, file extension matching, MIME type matching, PICS filtering, and URL/domain blocking. It has the ability to switch off filtering by certain criteria including username, domain name, source IP, etc. The configurable logging produces a log in an easy to read format. It has the option to only log text-based pages, thus significantly reducing redundant information (such as every image on a page).
NetTraf consists of a daemon that gets information from a Linux interface and sends it on the network to NetTraf clients. Clients then can use the information to show to the user how the connection is performing. This program is mostly useful with dial-up connections on a masqueraded server, so all users on the network know when the connection is active, and if there is too much traffic on the line. This package DOES NOT comes with any client applications; you can find them on the homepage. The author needs help to develop a Linux client.
npadmin is a command line tool to administer network printers. It is based on the concepts of JetAdmin and other vendor's tools but is designed to be scriptable. It uses SNMP to query the common printer MIB (RFC 1759) and return information about the printer. There is a surprising amount of information available in the common printer MIB and since the vendors all use their private MIBs, this appears to be the only tool that makes it available.
Performance Co-Pilot (PCP) is a framework and set of services for supporting system-level performance monitoring and performance management. It provides a unifying abstraction for all of the interesting performance data in a system, and allows client applications to easily retrieve and process any subset of that data using a single API. A client-server architecture allows multiple clients to monitor the same host, and a single client to monitor multiple hosts. Archive logging and replay are integrated so that a client application can use the same API to process real-time data from a host or historical data from an archive.