ResumeFodder produces output in Microsoft Word 2003 XML format. Every modern version of Microsoft Word handles these files great, so if you'll always be working with Word then you can stop reading here!
However, what if don't have access to Microsoft Word on your machine (e.g. you're on Linux, you have strong free software beliefs, you simply don't want to buy it, etc)? Unfortunately, the 2003 XML format variation is not well supported by LibreOffice, or online options such as Google Docs or Word Online.
Fortunately, the most recent default Word format IS well-supported by LibreOffice and Word Online. So if you want, you can convert your resume output to the latest Word format through one of these options:
Microsoft Word seems to be the most common file type expected by recruiters. However, you can use Word or LibreOffice to export your resume as PDF or HTML if you wish.