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.
python-tracing provides the Python library "tracing" to help with logging debug messages. This module provides a couple of functions for logging debug messages. It is sometimes practical to add a lot of debugging log messages to a program, but having them enabled all the time results in very large log files. Also, logging that much takes quite a bit of time. This module provides a way to turn such debugging or tracing messages on and off, based on the filename in which they occur.
x11vis is a visual and interactive tool for debugging X11 clients. Unlike other tools such as xtrace, it displays human readable IDs on all requests, no matter at which point in time the information becomes available. To help you cope with large amounts of data, it displays only the most important information by default, automatically folds sequences of boring requests, allows you to filter by packet type or client, and provides markers for navigation. Instead of assigning a number to each connection, it displays the command line with which that client was started.
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.
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.
pymiproxy is a small, lightweight, man-in-the-middle embeddable proxy capable of performing HTTP and HTTPS (or SSL) inspection. The proxy provides a built-in certificate authority that is capable of generating certificates for SSL-based destinations. Pymiproxy is also extensible, and provides two methods for extending the proxy: method overloading and a pluggable interface. It is ideal for situations where you're in dire need of a proxy to tamper with out- and/or in-bound HTTP data.
ftracer is a simple user space implementation of a Linux kernel style function tracer. It allows you to trace every call in instrumented user applications. It is useful for debugging and performance analysis due to its fine grained time stamp. This allows you to do control flow oriented debugging without any special instrumentation. So if the program does something unexpected, it's easily possible to look at the function calls before that, and use that to deduce the cause of the problem. ftracer relies on gcc generating a call on top of every function call. The tracing slows every function call down (about 3x). The tracing is per thread and does not create a global bottleneck. It supports a dump function in C, directly callable by the program or on exit, and a gdb function to dump from gdb.