Enterprises often grow through mergers and acquisitions. As a result, enterprises usually end up with disparate brands of data warehouses and BI clients. This talk introduces some of the challenges and methods of bridging such “Islands of BI”. We first briefly introduce OnLine Analytical Processing (OLAP), and the real-time performance it provides for ad hoc multi-dimensional queries. We then describe how the Multi-Dimensional eXpression (MDX) query language and XMLA are becoming brand-independent standards for BI queries from Excel, SAP Voyager, Cognos, MicroStrategy, and other BI client applications. Finally, we overview architectures, some using surprisingly-simple direct connections, for bridging BI client applications to other brands of BI servers.