Perform the following steps to build the web copy:

1. Make symbolic links in the xml directory with the names xerces-2 and
   xerces-3 that point to the source code of Xerces-C++ 2 and 3-series
   respectively.

2. Copy xerces-2 and xerces-3-specific entities from
   xerces-2/doc/style/dtd/entities.ent and
   xerces-3/doc/style/dtd/entities.ent to xml/style/dtd/entities.ent.

3. Run create.sh

4. Regenerate Doxygent documentation in xerces-2/doc/html/apiDocs-2
   and xerces-3/doc/html/apiDocs-3.

2. Copy doxygen API documentation as apiDocs-2 and apiDocs-3 into
   html/.

3. Check around that nothing is broken (make sure you can navigate
   to the generated doxygen docs).