Compile-Time Assertions & Debugging
- It's common practice to use assertions to check invariants at runtime, but assertions can be equally useful at compile time for doing things like checking arrays for proper size and order.
- http://www.ddj.com/dept/debug/184402051

Pantheios
- A C/C++ logging API library, offering an optimal combination of 100% type-safety, efficiency, genericity and extensibility. [Open Source]
- http://pantheios.sourceforge.net/

CppUnit
- A C++ unit testing framework that started as a port of JUnit to C++.
- http://cppunit.sourceforge.net/cppunit-wiki

mpatrol
- A powerful debugging tool that attempts to diagnose run-time errors that are caused by the wrong use of dynamically allocated memory. [Open Source, LGPL]
- http://www.cbmamiga.demon.co.uk/mpatrol/

LeakTracer
- Library for tracing and analyzing memory leaks in C++ programs. [Public Domain]
- http://www.andreasen.org/LeakTracer/

log4cplus
- Port of the log4j logging library to C++.
- http://log4cplus.sourceforge.net/

mockpp
- Mock Objects for C++, a platform independent generic unit testing framework for C++. Its goal is to facilitate developing unit tests in the spirit of Mock Objects for Java, EasyMock and jMock.
- http://mockpp.sourceforge.net/index-en.html

Memory Supervision System
- Helps in the infamious task of finding bugs related to dynamical memory during the development of programs. [Open Source, GPL]
- http://hem.passagen.se/blizzar/mss/

Log4cpp
- A library for flexible logging to files, syslog, IDSA and other destinations, modeled after the Log4j Java library. [Open Source, LGPL]
- http://log4cpp.sourceforge.net/

Libcwd
- A thread-safe library to support C++ developers with debugging their applications. It includes support for ostream-based debug output to custom debug channels, memory allocation debugging and run-time support like printing source file locations and demang
- http://libcwd.sourceforge.net/