Following an extremely education experience at LOD-LAM, I have added VIAF integration to EADitor's code base for personal and corporate names. Additionally, place names are now AACR2-compliant (except for Malaysia). You can read more about the changes and view the code here: http://eaditor.blogspot.com/2011/06/improving-authority-control-in-eaditor.html
EADitor now offers out of the box:
LCSH for subjects
geonames for geographical places (including georeferencing collections on indexing into the public interface and kml/openlayers-driven mapping)
VIAF for personal and corporate names
If you would like to or have already installed EADitor, please refer to the subversion updating instructions on the wiki: http://code.google.com/p/eaditor/wiki/StayingCurrentWithSubversion. Since this is a beta, currently, there is no synchronization of terms to the vocabulary service after the initial addition of elements into a finding aid. However, each service has REST APIs, and thus it will be possible to do so in a later release of EADitor.
I'd like to be able to provide access to controlled vocabulary terms for <genreform>, but Getty's AAT is the only reference I can think of, and since it isn't free, I can't use it. Are there other services available?
American Numismatic Society