lcdtest is a utility to display monitor test patterns. It was originally written for use with LCD monitors, and may be useful in finding pixels that are stuck on or off as well as for adjustment (automatic or manual). However, it can be useful for CRT monitors as well. lcdtest uses the SDL library, and has been used on Linux with X and on Windows, but may work on other platforms supported by SDL.
liboping is a C library for measuring network latency using ICMP echo requests. It can send to and receive packets from multiple hosts in parallel, which is nice for monitoring applications. Both IPv4 and IPv6 are supported transparently for the programmer and user. A program called oping is included to show the simplicity and potential of the library and provide the functionality at the command line.
ICPLD (Internet Connection Performance Logging Daemon) is a connection monitor that sends ICMP requests to IP addresses of your choice and monitors if your machine has a working network connection. It logs failed attempts to reach the hosts, and will stamp a log as soon as a reply is received. It keeps track of when and for how long the connection was unavailable and records both total down time and each occasion of interrupted connection. It supports IPv6 and can execute a command whenever a connection goes up or down, which is useful for alerting users.
Passwd_exp notifies users via email of upcoming password or account expiration. Its simple modular architecture allows you to perform expiration checks on any data source you use (SQL databases, LDAP...), send expiration warnings only to desired users or group and on selected days only. Administrators can use it to review expired accounts in the system. Support for Linux and Solaris shadow (including LDAP and NIS systems) and BSD passwd systems is included.
JSTUN is a STUN (Simple Traversal of UDP (User Datagram Protocol) through NAT (Network Address Translation)) implementation. STUN provides a means for applications to discover the presence and type of firewalls or NATs between them and the public Internet. In the presence of a NAT, STUN can also be used by applications to learn the public Internet Protocol (IP) address assigned to the NAT.
MCS MyVoIP very accurately measures the quality and performance of Internet connections for Voice over IP (VoIP) usage by simulating UDP voice data traffic between a server and browser clients. Connections are tested for jitter and packet loss and rated for the supported level of sound quality. The VoIP test can be set to various codecs or customized by packet size, packet rate, and test length. The test can further be combined with a bandwidth speed test or network route diagnostics for more in-depth connection analysis.
Oculus Server Monitor uses a plain text, human readable protocol to export server information to any client that connects to it. It supports a plugin system for commands, an XML-style configuration file, and IP-based access control. Odie, the Oculus Daemon InterfeacE, is a rich Web application that polls a list of hosts for their status.
pwatch is a set of tools for analyzing what a process is doing. Only the "io" command is currently implemented. It presents I/O activity in a nice ncurses screen and allows you to sort by the read/write speed or the number of bytes read/written since the start of the program. It was written to easily detect which program is eating a lot of I/O bandwidth.