I've published at:
a library to import/export EAD files into Ruby objects. It doesn't
support all of the elements in EAD because I haven't gotten around to it
yet, but adding an element is a very simple thing to do.
Besides being able to import/export whole files to and from memory it
can also process them in pieces. This was developed for the Portuguese
national archives and I've created/imported EAD files with 100MB with no
The library is licensed under the LGPL.