How do I get a machine-readable list of sites?

OAI-PMH

You can download the records in Dublin Core format from the OAI-PMH interface.

ListFriends?

Just the OAI base URLs can be accessed via a ListFriends listing.

Plain-Text

To get the full record (except for email addresses and internal data) use the plain text listing.

Plain-text listings are in RFC header-style format: multi-line values are prefixed by a single space, and records are separated by a single, empty line.

If you require more detailed data please contact me specifying what you need ("how do I download ROAR" type emails will be ignored).

Google Earth Overlay

To get a Google Earth overlay-format file (KML) change the action to 'kml' e.g.

http://roar.eprints.org/?action=kml&order=recordcount

Google Maps Overlay

Stuart Lewis has made a 'mash-up' of ROAR, OpenDOAR and geo-location data to create a queriable Google Maps interface (warning! may time some time to load).