With the release of R12, Oracle had retired Client ADI, a tool that had been used for many things, amongst which was making FSG reports look pretty, and allowing users to drilldown into the financial information displayed on the reports to get more detailed information.
With the retirement of Client ADI, Oracle began to push Report Manager, a Report Repository tool that allows users to drill-down into FSG reports, as long as they have a report-specific Excel template assigned to them. I've been using Report Manager for some time, and I think it is a great tool to provide Management with access to the financial reports they need, as well as allowing them to discover what is behind the numbers (without bothering the folks in Accounting).