The curator in our libraries' Special Collections Department tells me that
BBEdit works very well with SGML / XML on the Mac.  There's also a
hierarchical database system with good scripting support that's worth
looking into, called Userland Frontier, for the Mac.  There's a very well
written book about it by, I think, Matt Neuberg, published by O'Reilly.

One of the intended uses of Frontier is to support large HTML sites, but
the mechanisms would also work with EAD.  There's a version of Frontier
for Windows, but when I've experimented with it, it has crashed too often
for me to recommend it.  I think the Mac version is not so buggy.  You can
get a free version of it via the Internet.

(By the way, that's the BBEdit that you have to buy, not the free BBEdit
Lite.)

-- Kevin Cawley
   Archivist
   University of Notre Dame
   [log in to unmask]