net-status-monitor is a simple console script to test whether Internet connectivity is working. If it is, the script tells you the external IP address (in case your dynamic DNS provider is down). If not, it tries to find the point where the connectivity fails. The output is quite simple, so you can put it on your grandmother's PC. "Just tell me what the read line says" should give you enough information.
Monjo is a Web application that helps monitoring a small to medium network of servers. It offers easy customization of notifications in case of network failures and is designed to allow for easy addition of new services that need to be monitored. It's internationalized and includes a Web interface in English and German. It currently supports notifications by email and can check services using ping, SMTP, HTTP, POP3, and IMAP4.
Treewatch watches a directory for a specified type of file to change. When one of the files changes, treewatch runs a program of the user's choice. By default, treewatch will watch the current directory and run "make" when changes are detected in files ending in .cpp, .c, or .h. The user can specify any number of directories to watch, any number of file types to watch for, and any command line to run.
LogAnalyzer is a Web front-end for syslog and other network event data. It provides easy browsing, searching, basic analysis, and some graphics. Data is taken from databases or plain syslog text files, so LogAnalyzer does not require changes to an existing logging infrastructure. Depending on the log data present, it can process syslog messages, Windows event log entries, and some more exotic things. Its troubleshooting support enables users to quickly find solutions to problems seen in the log data. LogAnalyzer was previously called phpLogCon, and has been renamed since v3.