For the Open Archives Initiative-Protocol for Metadata Harvesting (OAI-PMH) there are two groups of 'participants': Data Providers and Service Providers. Data Providers (open archives, repositories) provide free access to metadata, and may, but do not necessarily, offer free access to full texts or other resources. OAI-PMH provides an easy to implement, low barrier solution for Data Providers. Service Providers use the OAI interfaces of the Data Providers to harvest and store metadata. Note that this means that there are no live search requests to the Data Providers; rather, services are based on the harvested data via OAI-PMH.
Koha at present can only act as a Data Provider. It can not harvest from other repositories. The biggest stumbling block to having Koha harvest from other repositories is that MARC is the only metadata format that Koha indexes natively. Visit http://www.oaforum.org/tutorial/english/page3.htm for diagrams of how OAI-PMH works.
Learn more about OAI-PMH at: http://www.openarchives.org/pmh/
To enable OAI-PMH in Koha edit the OAI-PMH preference. Once enabled you can visit http://YOURKOHACATALOG/cgi-bin/koha/oai.pl to see your file.
format: vs: metadataPrefix: vs metadataNamespace: http://veryspecial.tamil.fr/vs/format-pivot/1.1/vs schema: http://veryspecial.tamil.fr/vs/format-pivot/1.1/vs.xsd xsl_file: /usr/local/koha/xslt/vs.xsl marcxml: metadataPrefix: marxml metadataNamespace: http://www.loc.gov/MARC21/slim http://www.loc.gov/standards/marcxml/schema/MARC21slim schema: http://www.loc.gov/MARC21/slim http://www.loc.gov/standards/marcxml/schema/MARC21slim.xsd oai_dc: metadataPrefix: oai_dc metadataNamespace: http://www.openarchives.org/OAI/2.0/oai_dc/ schema: http://www.openarchives.org/OAI/2.0/oai_dc.xsd xsl_file: /usr/local/koha/koha-tmpl/intranet-tmpl/xslt/UNIMARCslim2OAIDC.xsl