Bootchart is a tool for performance analysis and visualization of the GNU/Linux boot process. Resource utilization data and process information are collected during the boot process and can later be displayed in a PNG, SVG or EPS chart.
Free Java monitoring library to easily instrument apps to measure performance detail over time with minimal overhead. Has dashboard, SVG graphs. Extends Jamon and its statistical data, same usage. http://www.e-peas.com/opensla/. JMX, SNMP planned.