Composite applications in Lotus Notes 8, aka business mashups, allow organizations to make use of their current applications and systems in a way that is very easy to use. Organizations that create Notes business mashups really help their employees and improve their effectiveness. Employees stop losing valuable time switching between applications, searching for associated content, and copying and pasting information. Now, they are able to access relevant information from multiple systems in one integrated view, helping to simplify their work process.
Notes composite applications can include applications built with many different programming languages, including Lotus Notes applications (Domino), Java client applications and Microsoft .NET applications, amongst others. To better understand the ideas behind business mashups, I recommend you take a look at this Smart Assist demo from IBM.
However, no real-world composite app will ever be complete without documents integration.
If an organization uses SharePoint for document management, what can be more natural than integrating SharePoint documents into its business mashups?