I see Oracle has a comprehensive Integration Repository online (http://irep.oracle.com/).
Question is… how can one call these procedures? Do I have to do it through PL/SQL? Or do all these functions/procedures have corresponding web services exposed automatically?
Oracle is moving to SOA big time with tools and infrastructure support for BPEL, WebServices and ESB. Some parts of Oracle EBS already have web services api, others will surely follow in the future.
Here’s some documentation on how to integrate peoplesoft crm with oracle ebs: http://www.oracle.com/technology/pub/articles/bpel_cookbook/pravin.html