Opsview Core is a network monitoring software application. It solves the challenges of monitoring modern IT and network systems. It is a drop-in replacement for Nagios Core, with full support for its plugins and 100% compatibility. It is easy to install and configure and is ideal for monitoring applications networks, and Windows, Linux, and Unix servers. VMWare, KVM, Xen, and Microsoft Hyper-V are supported, and Amazon EC2 and other cloud services can be monitored. It works with Opsview Mobile to allow you to monitor your systems on the go.
rules2mrtg is a tool that creates MRTG data traffic graphs derived from iptables's internal traffic statistics for the local machine for every configured IP number/ethernet alias. You can also define ports or port ranges to be monitored per IP address. This avoids problems with using SNMP and aliased interfaces.
SysopView shows information in a visually attractive way, like computers in movies do. The idea is that it can show information relevant to system administrators non-comprehensible for non-technical personnel, while still looking attractive even if you don't know what is shown. The current version can show nagios status data, webcam streams (mjpeg, jpeg, and video4Linux), and VNC, has a built-in terminal emulator in which regular text applications can be run, can sniff the network (including remotely) and dissect streams and show pictures which are sniffed, can show external bitmaps (from, for example, mrtg and rrdtool), and can scroll text (currently showing output of rssfeeds).