Index: gc_lang/fr/config.ini
==================================================================
--- gc_lang/fr/config.ini
+++ gc_lang/fr/config.ini
@@ -29,13 +29,14 @@
 
 # Firefox
 fx_identifier = French-GC@grammalecte.net
 fx_name = Grammalecte [fr]
 
-fx_standard_path = C:\Program Files\Mozilla Firefox\firefox.exe
-fx_dev_path = C:\Program Files\Firefox Developer Edition\firefox.exe
-fx_nightly_path = C:\Program Files (x86)\Nightly\firefox.exe
+win_fx_dev_path = C:\Program Files\Firefox Developer Edition\firefox.exe
+win_fx_nightly_path = C:\Program Files (x86)\Nightly\firefox.exe
+linux_fx_dev_path = /usr/bin/firefox
+linux_fx_nightly_path = /usr/bin/firefox
 
 
 # Thunderbird
 tb_identifier = French-GC-TB@grammalecte.net
 tb_name = Grammalecte [fr]

Index: make.py
==================================================================
--- make.py
+++ make.py
@@ -11,10 +11,11 @@
 import datetime
 import argparse
 import importlib
 import unittest
 import json
+import platform
 
 from distutils import dir_util, file_util
 
 import dialog_bundled
 import compile_rules
@@ -348,15 +349,17 @@
                         tests.perf(sVersion, hDst)
 
             # Firefox
             if xArgs.firefox:
                 with helpers.cd("_build/xpi/"+sLang):
-                    os.system('jpm run -b "' + dVars['fx_dev_path'] + '"')
+                    spfFirefox = dVars['win_fx_dev_path']  if platform.system() == "Windows"  else dVars['linux_fx_dev_path']
+                    os.system('jpm run -b "' + spfFirefox + '"')
 
             if xArgs.web_ext:
                 with helpers.cd("_build/webext/"+sLang):
-                    os.system(r'web-ext run --firefox="' + dVars['fx_nightly_path'] + '" --browser-console')            
+                    spfFirefox = dVars['win_fx_nightly_path']  if platform.system() == "Windows"  else dVars['linux_fx_nightly_path']
+                    os.system(r'web-ext run --firefox="' + spfFirefox + '" --browser-console')            
 
             # Thunderbird
             if xArgs.thunderbird:
                 os.system("thunderbird -jsconsole -P debug")
         else: