Federate Search: Targets

Dear list


if i'm not wrong, federate search for libraries comes down to OAI-PMH, 
Z39.50 (SRU/SRW - Zing is dead isn't it?) and Open Search.


For OAI-PMH : http://www.openarchives.org/Register/BrowseSites


For Z39.50 : http://irspy.indexdata.com/


For Open Search it is the world widespread web.


Do you know other comprehensive resources for those targets ?




Thank you,


Stefan Kandera