OXPS file format
Microsoft XPS Viewer
The installation of a program that can open the .oxps file is not done on the computer. The default XPS document format in Windows 8 is the oxps format. So, these files are created when printing is done to a Microsoft XPS Document Writer (MXDW) printer on a Windows 8 computer.
Attention should be taken when sending files to others because the XPS format for these file types is much more popular than the OXPS file. The latest software would open it while the older version would pose a challenge. Consider converting the OXPS file to XPS before sending it to enable people to access the document. Some might know how to convert, while others would not attempt. This is a big challenge with Windows 8 because OXPS is the default extension for saving documents.