  By the end of the late 90's the Open Archives Initiative needed direction to
insure its improvement and thus, created the Open Archives Initiative Protocol
for Metadata Harvesting (OAI-PMH) standard. The movement showed a rise in
popularity, followed by a decline then a relative stabilization. This process
was essentially a way to ensure the viability of open archive repositories.
However, a meta-catalog containing an ensemble of repositories was never
established, which lead to confusion of what could be found in said catalogs.
  This study ultimately aims to find out what repository content can be found
and where with the use of the 6 key meta-catalogs. Although they undoubtedly
have numerous limitations pertaining to the available data, this article seeks
to compare the common data in each meta-catalog and estimates which
repositories are found within them (with approx. less than 1% in common within
the 6 meta-catalog).
  Decisively, this paper identifies the need to collate this data (with a total
of 42.3% OAI-PMH repositories specific to each meta-catalog) and improve
current search tools, hence portraying the benefits of a comprehensible single
unifying meta-catalog for end users.
