Some may know how to convert the file themselves however, many others will likely not even try. If you want people to be able to open your document without problems, you should consider converting your OXPS file back to XPS before sending. However, if their software is a little older, they could have problems. If they have newer software, they will probably be able to open the file without problems. Since the XPS format for these types of files is still much more popular than the OXPS file, you should pay special attention before sending a file to others. However, because the XPS file extension is the one that is most commonly used, many people will have an issue if they try to open an OXPS file, unless they have very current software installed on their computer. The difference is that the an OXPS file is considered an “open” format. The format of the OXPS file is the same as an XPS format. Most people are very familiar with a PDF file and an OXPS is very similar in nature to a PDF file. This file container holds a variety of different types of content and presents the content in a paper-like fashion.

A file that uses the file extension of OXPS is basically a “container”.

Firefox os x xps document viewer plugin