Perhaps Doxygen can already link to classes in another project. Quoting http://www.stack.nl/~dimitri/doxygen/manual/features.html :
"Doxygen can also automatically generate links to existing documentation that was generated with Doxygen or with Qt's non-public class browser generator. For a Qt based project this means that whenever you refer to members or classes belonging to the Qt toolkit, a link will be generated to the Qt documentation. This is done independent of where this documentation is located!"
Perhaps Doxygen can already link to classes in another project. Quoting http:// www.stack. nl/~dimitri/ doxygen/ manual/ features. html :
"Doxygen can also automatically generate links to existing documentation that was generated with Doxygen or with Qt's non-public class browser generator. For a Qt based project this means that whenever you refer to members or classes belonging to the Qt toolkit, a link will be generated to the Qt documentation. This is done independent of where this documentation is located!"