diff -ur mongrel-0.3.13.3orig/bin/mongrel_rails mongrel-0.3.13.3/bin/mongrel_rails
--- mongrel-0.3.13.3orig/bin/mongrel_rails	2006-07-05 09:41:10.000000000 -0700
+++ mongrel-0.3.13.3/bin/mongrel_rails	2006-07-10 20:13:48.000000000 -0700
@@ -32,7 +32,8 @@
       ['-S', '--script PATH', "Load the given file as an extra config script.", :@config_script, nil],
       ['-G', '--generate CONFIG', "Generate a config file for -C", :@generate, nil],
       ['', '--user USER', "User to run as", :@user, nil],
-      ['', '--group GROUP', "Group to run as", :@group, nil]
+      ['', '--group GROUP', "Group to run as", :@group, nil],
+      ['', '--prefix PATH', "URL prefix for Rails app", :@prefix, '/']
     ]
   end
 
@@ -64,7 +65,7 @@
       :docroot => @docroot, :mime_map => @mime_map, :daemon => @daemon,
       :debug => @debug, :includes => ["mongrel"], :config_script => @config_script,
       :num_processors => @num_procs, :timeout => @timeout,
-      :user => @user, :group => @group
+      :user => @user, :group => @group, :prefix => @prefix
     }
 
     if @generate
@@ -108,8 +109,8 @@
           debug "/", what = [:files]
         end
 
-        log "Starting Rails with #{defaults[:environment]} environment ..."
-        uri "/", :handler => rails(:mime => mime)
+        log "Starting Rails with #{defaults[:environment]} environment on #{defaults[:prefix]} ..."
+        uri defaults[:prefix], :handler => rails(:mime => mime, :prefix => @prefix)
         log "Rails loaded."
 
         log "Loading any Rails specific GemPlugins"
diff -ur mongrel-0.3.13.3orig/lib/mongrel/rails.rb mongrel-0.3.13.3/lib/mongrel/rails.rb
--- mongrel-0.3.13.3orig/lib/mongrel/rails.rb	2006-07-05 09:41:10.000000000 -0700
+++ mongrel-0.3.13.3/lib/mongrel/rails.rb	2006-07-10 15:52:38.000000000 -0700
@@ -136,6 +136,7 @@
         ops[:environment] ||= "development"
         ops[:docroot] ||= "public"
         ops[:mime] ||= {}
+        ops[:prefix] ||= "/"
 
 
         $orig_dollar_quote = $".clone
@@ -148,6 +149,9 @@
         if ActionController::Base.allow_concurrency
           log "[RAILS] ActionController::Base.allow_concurrency is true.  Wow, you're very brave."
         end
+
+	ActionController::AbstractRequest.relative_url_root = ops[:prefix]
+
         @rails_handler = RailsHandler.new(ops[:docroot], ops[:mime])
       end