x11vnc allows one to remotely view and interact with real X displays (i.e. a display corresponding to a physical monitor, keyboard, and mouse) with any VNC viewer. It is designed to be compatible with all Unix variants and Mac OS X, and depends on a small set of standard libraries. It supports SSL/TLS and VeNCrypt encryption, Unix password logins, single port access, Zeroconf, file transfer, and UltraVNC extensions. It is part of the LibVNCServer project.
Alerttail monitors a given file and executes a list of actions when a user-defined text pattern has been written to the file. For example, the user can pop up a GTK notification window when a certain message is written to a log file. Actions can be alerttail built in actions (GTK notify action, geoipLocalization action, or filtering text action) or a custom user defined shell command action. A Qt 4 GUI frontend helps with configuration.
Nall is a small status icon application that discreetly fits into the system tray. Its purpose is to spawn a list of user scripts periodically and display one line of output per script in a tooltip window. Thus, it is possible to "monitor" any kind of event that can be detected with a script. Nall does not care about the return values of the scripts it runs, but only displays their output. It is also easy to interface nall with Nagios plugins.
Seetxt is a lightweight text file and man page viewer for X windows. It maintains "document meta-data" for each user, allowing them to automatically keep bookmarks and highlights for read-only system files. It also has a "server mode" so that command line requests can be sent to a single running server rather than starting multiple instances. Other features include hypertext-style apropos (man page) searches, file monitoring, multi-level regular expression searching, a command history, and nice little toggle lights on the interface for the server and file monitor. There's also cross-application drag-n-drop support, and handy little features that allow you to view the output of shell commands and process the text buffer with an external command (sed, awk, grep, perl, etc.) Seetxt is POSIX compliant.
MN Viewer (Mobile Network Viewer) is a lightweight framework designed for system administrators who would like to be able to monitor many aspects of their network from their mobile phone. It allows for very simple expansion using simple PHP plugins. It is designed to integrate with other monitoring tools such as Cacti.
xsysguard is a resource-friendly system monitor based on Imlib2. The main features include a powerful configuration file format, full alpha channel support, configurable widgets, and many data sources implemented as modules. For example, the daemon module allows you to monitor remote machines, and the file module can parse files with scanf or regular expressions.
Inject is program which can generate, inject and withdraw BGP routes, with a primary focus on network testing. It supports route and peer flapping, generation of random routes with (pseudo) random BGP attributes via a Cisco like CLI. Other features include a configuration file based on XML, test cases, help functions, and displaying of peer and route information.