diff -ur a/lib/configure.py b/lib/configure.py
--- a/lib/configure.py	2020-06-01 21:11:22.000000000 +0100
+++ b/lib/configure.py	2020-06-02 15:39:52.234788930 +0100
@@ -682,7 +682,7 @@
 \Format xbm        xbm     XBM                    "" "%s"	"%s"	""	"image/x-xbitmap"
 \Format xpm        xpm     XPM                    "" "%s"	"%s"	""	"image/x-xpixmap"'''
     path, iv = checkViewerNoRC('a raster image viewer',
-        ['xv', 'gwenview', 'kview',
+        ['xdg-open','xv', 'gwenview', 'kview',
          'eog', 'xviewer', 'ristretto', 'gpicview', 'lximage-qt',
          'xdg-open', 'gimp-remote', 'gimp'],
         rc_entry = [imageformats])
@@ -731,7 +731,7 @@
 \Format html_table html   "HTML Table (for spreadsheets)"      "" "" "%%"    "document"	"text/html"
 \Format oocalc     ods    "OpenDocument spreadsheet" "" "" "%%"    "document"	"application/vnd.oasis.opendocument.spreadsheet"'''])
  #
-    checkViewer('an HTML previewer', ['firefox', 'mozilla file://$$p$$i', 'netscape'],
+    checkViewer('an HTML previewer', ['xdg-open', 'firefox', 'mozilla file://$$p$$i', 'netscape'],
         rc_entry = [r'\Format xhtml      xhtml   "LyXHTML"              y "%%" ""    "document,menu=export"	"application/xhtml+xml"'])
  #
     checkEditor('a BibTeX editor', ['jabref', 'JabRef',
@@ -745,7 +745,7 @@
     #checkProg('a Postscript interpreter', ['gs'],
     #  rc_entry = [ r'\ps_command "%%"' ])
     checkViewer('a Postscript previewer',
-                ['kghostview', 'okular', 'qpdfview --unique',
+                ['xdg-open', 'kghostview', 'okular', 'qpdfview --unique',
                  'evince', 'xreader',
                  'gv', 'ghostview -swap', 'gsview64', 'gsview32'],
         rc_entry = [r'''\Format eps        eps     EPS                    "" "%%"	""	"vector"	"image/x-eps"
@@ -756,7 +756,7 @@
     # maybe use "bestApplication()" from https://github.com/jleclanche/python-mime
     # the MIME type is set for pdf6, because that one needs to be autodetectable by libmime
     checkViewer('a PDF previewer',
-                ['pdfview', 'kpdf', 'okular', 'qpdfview --unique',
+                ['xdg-open', 'pdfview', 'kpdf', 'okular', 'qpdfview --unique',
                  'evince', 'xreader', 'kghostview', 'xpdf', 'SumatraPDF',
                  'acrobat', 'acroread', 'mupdf',
                  'gv', 'ghostview', 'AcroRd32', 'gsview64', 'gsview32'],
@@ -769,7 +769,7 @@
 \Format pdf7       pdf    "PDF (cropped)"         "" "%%"	""	"document,vector"	""
 \Format pdf8       pdf    "PDF (lower resolution)"         "" "%%"	""	"document,vector"	""'''])
     #
-    checkViewer('a DVI previewer', ['xdvi', 'kdvi', 'okular',
+    checkViewer('a DVI previewer', ['xdg-open', 'xdvi', 'kdvi', 'okular',
                                     'evince', 'xreader',
                                     'yap', 'dviout -Set=!m'],
         rc_entry = [r'''\Format dvi        dvi     DVI                    D  "%%"	""	"document,vector,menu=export"	"application/x-dvi"
@@ -778,7 +778,7 @@
         # Windows only: DraftDVI
         addToRC(r'\Format dvi2       dvi     DraftDVI               ""	""	""	"vector"	""')
     #
-    checkViewer('an HTML previewer', ['firefox', 'mozilla file://$$p$$i', 'netscape'],
+    checkViewer('an HTML previewer', ['xdg-open', 'firefox', 'mozilla file://$$p$$i', 'netscape'],
         rc_entry = [r'\Format html      "html, htm" HTML                H  "%%"	""	"document,menu=export"	"text/html"'])
     #
     checkViewerEditor('Noteedit', ['noteedit'],