If you have Doxygen (www.doxygen.org) available (the executable doxygen should be in the path command) then executing
make doxydocin the project root directory will result in the Doxygen documentation being generated and stored in the doxydoc folder in the project root.
In order to view the documentation, open a browser and open the file
projectroot/doxydoc/html/index.html
By default, running Doxygen will generate documentation for only the OS project. Documentation will not be generated for the other COIN-OR projects in the project root. In the doxydoc folder is a configuration file doxygen.conf. This configuration file contains the EXCLUDE parameter
EXCLUDE = Cbc \ Cgl \ Clp \ CoinUtils \ cppad \ SYMPHONY \ Vol \ DyLP \ ThirdParty \ Osi \ include
This file can be edited, and any project for which documentation is desired, can be deleted from the EXCLUDE list.