Java Debugging with Statement Aspects provides the possibility to skip certain statements from being executed during debugging. It lets you add your custom logic before and after execution of certain statements. It provides the possibility of tracing at the granularity of line numbers without touching the source code.
KEDR is a framework to facilitate dynamic analysis of kernel modules in Linux ("KEDR" is an acronym for "KErnel-mode Drivers in Runtime"). KEDR allows you to intercept the calls that a kernel module makes to the functions exported by other modules and by the kernel proper. The tools provided by the framework can record the arguments and return values of these functions to a trace, perform fault simulation according to user-defined scenarios, and check the kernel modules for memory leaks and some other kinds of problems. Custom data collection and analysis tools for the Linux kernel can also be built on top of KEDR framework.
PHP Error aims to make understanding initial error reporting as fast as possible. When an error strikes, you get a full syntax-highlighted stack trace, with code snippets from the relevant files and improved error messages, displayed with CSS3. It works for AJAX requests, too, with no JS changes or plugins required.
SpurTracer is a push-notification based monitoring solution for heterogenous loosely coupled IT infrastructures. It complements a service-endpoint monitoring solution like Nagios with a component-level interface auto-discovery. It automatically provides a certain level of functional tracing along with many non-functional measurements (e.g. call, error and timeout rates, interface latency, component execution, etc.). While being zero config itself, SpurTracer relies on you adding push notification support to the components you want to monitor. The best way to use SpurTracer is by adding punctual tracing to components in your infrastructure on-demand.