A WORKBOOK file contains a workbook created by Xamarin Workbooks, a computation environment for C# developers available as a standalone program or with Visual Studio. It stores documentation information and sample code that allow developers to learn C# by experimenting and creating code.

There are three types of workbooks that all use the .workbook file extension: Plain text - A workbook saved in the CommonMark text format. Package - A workbook that saves a directory of resource files used in the workbook, which include an index.workbook plain text file, images, and other files. Archive - A workbook saved as a Zip-compressed archive, which is used to transfer workbook packages online. NOTE: Workbooks may be created for various frameworks, including Android, iOS, macOS, and Windows.