Standard browsers use SVG for the graphics rendering.In legacy Internet Explorer graphics are drawn using VML.The file format is closely based on the comma separated values (CSV) text file format.Live Graph defines a few small but important extensions, such as data column header definitions and file description annotations.Live Graph provides an open and very thoroughly documented API.
One of the key features of Highcharts is that under any of the licenses, free or not, you are allowed to download the source code and make your own edits.
NSClient on the windows boxes and nagios-statd on the linux stuff to monitor running processes, disk usage, etc.
We looked at both Nagios and Zabbix for our monitoring.
The plotter reads the Live Graph data file (or any other CSV file) and plots the data series contained therein on the screen.
The plotter has two distinctive features which are not available elsewhere in this combination: The Live Graph framework provides an open standard for data files containing transferable data logs.
Zabbix won after a short evaluation, mainly due to ease of deployment and functionality (for example, Zabbix includes graphing as a core function while Nagios requires a plugin). Cacti is a very good web-based frontend to RRDTool, providing very handy graphs and stats.