Wikipedia
IcyOwl
IcyOwl is an Open Source C++ Integrated Development Environment(IDE) distributed under GNU General Public License. It is written in C++ and wxWidgets API. IcyOwl is Cross-Platform, which means that it runs on many Operating System such as Microsoft Windows and Linux. Mac OS port is still unavailable as of now.
It uses doxygen to generate class tree, but only supports one compiler, that is GCC/ MinGW.
It is now going through a major code changes since the developer saw problems implementing the class browser using doxygen.