1. GoogleTest: http://code.google.com/p/googletest/
Google's framework for writing C++ tests on a variety of platforms (Linux, Mac OS X, Windows, Cygwin, Windows CE, and Symbian). Based on the xUnit architecture.
2. CppUnitLite: http://c2.com/cgi/wiki?CppUnitLite
Light-weight CppUnit
3. CppUnit: http://sourceforge.net/projects/cppunit/