At this dir you may find:

Here you will find all the custom widgets required to
support the available Presentations. As you will see there
are also a number of sub folder. Each sub folder contains the
implementations of needed widgets for each Graphical Toolkit.
Please note that the files in those subfolders might not be
symmetric, there may not be both a FLFoo.hxx,.cxx and QtFoo.hxx,.cxx
since each Graphical Toolkit sometimes provide different functionality
our needs to extend that functionality vary accordingly.

Please note that each subfolder is named after the Graphical Toolkit
whose the contained widgets depend.

For more info please refer to the Doxygen documentation or
to the comments placed in the files themselves. 

- The CLAM development group