This module provides an Open Archives Initiative Protocol for Metadata Harvesting (OAI-PMH), interface to the Bibliography Module.
Currently it only exposes metadata from the biblio module; however if there was demand I believe that it could be made configurable to expose other node types as well.
Drupal 7 Update
This module will not be updated to Drupal 7, rather a new "Views" plugin module has been created to take it's place. This will allow OAI feeds to be created from any fields available to Views. Please see the Views OAI-PMH module.