ltrace is a debugging program which runs a specified command until it exits. While the command is executing, ltrace intercepts and records the dynamic library calls which are called by the executed process and the signals received by that process. It can also intercept and print the system calls executed by the program. The program to be traced need not be recompiled for this, so you can use it on binaries for which you don't have the source handy. You should install ltrace if you need a sysadmin tool for tracking the execution of processes.
jLouiss is a shared library for logging of start and return of Java methods together with their parameters and result values. Is is designed as an add-on to the JDKs 1.2, 1.3, and 1.4 by various vendors. The tracer output can be controlled by using regular expressions. jLouiss is designed on the JDK JVMDI interface (older releases used the JIT interface).
DBG is a PHP debugger and profiler. It makes it much easier to discover the origins of problems and bugs in PHP scripts. It's equipped with the ability to backtrace errors. It shows local and global variables as well as parameters which have been passed to all nested function calls at any point of execution. Among other things, it allows you to execute scripts in a step-by-step manner, set breakpoints (including conditional ones), evaluate expressions, and watch variables. The profiler allows you to find bottlenecks in PHP code at the functions level as well as the modules level and even the source lines level.
Bugloo is a source level debugger for the Scheme compiler Bigloo. It aims at helping to debug Bigloo programs compiled into JVM bytecode. It is implemented by means of the JVM Debugging Architecture, a set of standard APIs provided by Sun to make debuggers and profilers. Currently, Bugloo can debug Bigloo programs, Java programs, or a mix of both. It is based on the debugging model used in GDB and provides additional features like debug sessions, traces, memory debugging, programmable breakpoints and embeddable interpreters. It is a command-line debugger. For the sake of simplicity, it includes a graphical user environment for GNU Emacs or XEmacs.
CUT is a unit-testing framework for C, C++, and Objective-C. Unlike other unit testing tools, CUT doesn't strive to be an SUnit clone. It automates a lot of the drudge work often encountered when using other unit testing packages for the C family of programming languages. CUT may also be used to unit-test assembly language software in some circumstances.