You can open .pub files with LibreOffice Draw in the current version (Fresh). Note, that it is not perfect, and certain features in Publisher won't render correctly. Simple documents should be OK, complex designs with fancy effects probably won't work well. If you need portability you would be better off exporting the documents to PDF format in Publisher. The only guaranteed way to open the .pub file and for them to look as originally intended is in Publisher itself. If you use say InDesign or Serif PagePlus, you'd run into the same issue - proprietary file formats.
Edited by jonuk76, 12 October 2015 - 05:03 PM.