QuickProf is a simple runtime performance measurement tool for C++ code. It provides a rough performance estimate with minimal effort. This kind of feedback can be invaluable to developers who want to optimize performance where it matters.
A pretty primitive portable profiler for Java 5.0. It only produces "flat" profiles, has only experimental support for multithreaded code, and aims at minimal overhead.
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.