Kieker is a framework for continuous monitoring and dynamic analysis of distributed software systems. Being designed for continuous operation, it induces only a low overhead. The TraceAnalysis tool allows to analyze and visualize trace information.
jLlama is a desktop application to monitor servers over SSH. Any figure retrieved from the command line can be polled and graphed in real time. Out of the box, jLlama can graph CPU and Memory usage for Linux and Solaris servers.