When OneStream was first released, the application was deployed and used through a browser. However, due to compatability issues between different browsers, OneStream as an application can now be used through operating systems such as Windows, Mac OS X, and so forth.
Now that OneStream XF is available for use on operating systems, the compatability problems that the application use to face on browser windows is much more diminished. Not only that, but the Windows application version also provides enhanced performance and an application that can perform more tasks than the browser-based application (ie Excel add-ins were not available on the browser version but are available on the Windows version).
Besides offering a similar but improved version of the browser OneStream XF, the Windows version allows for better integration opportunitites and richer integration capabilities with the Microsoft Office Suite.