I am using a computer with Linux.
How can I view files with the XPS extension?
The developers of Ghostscript, Artifex, have an XPS Viewer for Linux which presumably has the same requirements as Ghostscript. The download page for the whole suite is here. Also, here is a page from Microsoft that lists XPS related products.
I think you should get Okular, since it's the best XPS viewer for Linux:
Okular is a universal document viewer based on KPDF for KDE 4. This means Okular works on multiple platforms, including but not limited to Linux, Windows, Mac OS X, *BSD, etc.
Okular combines the excellent functionalities of KPDF with the versatility of supporting different kind of documents, like PDF, Postscript, DjVu, CHM, XPS, ePub and others.
As part of the Ghostscript-related suite of GhostPDL page description languages, there is the commandline gxps which can...
gxps file.xps,The command to convert an XPS to PDF would be
gxps \
-o output.pdf \
-sDEVICE=pdfwrite \
input.xps