There are 2 file types use the .XBF file extension:
1. XCAF Binary 3D Model
An XBF file contains a CAD 3D model saved in the eXtended Open Cascade Technology Application Framework (XCAF), an Open Cascade Technology document format. It stores 3D model data, structure information, and attributes in binary format.
You can open XBF files with various Open Cascade software, such as CAD Processor, DMU Reviewer, Asset Revamping, CAD Assistant, and CAD Builder.
Updated: March 31, 2021
2. XAML Binary File
File created by Microsoft Visual Studio, A Windows SDK; contains a pre-parsed binary representation of a .XAML file produced by the XamlBinaryWriter class; intended to be write-once.
By producing the XBF file, loading and parsing performance becomes better, especially when loading XAML files that define large resources.
The XBF file will appear as App.xbf in the subdirectory of its related application.
NOTE: If you compile your XAML file into the XBF format you should still maintain the XAML in its text state so that it remains human-readable.
App.xbf - Default name given to the binary representation of the XAML file of each app.
Updated: July 21, 2013