Browser class now knows which implementations support which browsers.

firewatir/lib/firewatir.rb

@@ -1176,4 +1176,4 @@ def js_eval(str)
 end
 
 require 'watir/browser'
-Watir::Browser.module_eval "@@klass = FireWatir::Firefox"  
+Watir.default_browser ||= 'firefox'  

watir-common/lib/watir/browser.rb

@@ -1,16 +1,29 @@
 # watir/browser
 require 'watir/options'
+module FireWatir
+  autoload :Firefox, 'firewatir'
+end
+
 module Watir
+  autoload :IE, 'watir'
 
   module Browser
-    @@klass = nil
+    @@browser_classes = {
+      'ie' => 'Watir::IE', 
+      'firefox' => 'FireWatir::Firefox'
+    }
     class << self
       def new *args
-        @@klass.new *args
+        klass.new *args
       end
       def start *args
-        @@klass.start *args
+        klass.start *args
+      end
+      def klass
+        key = Watir.options[:browser]
+        eval @@browser_classes[key] # this triggers the autoload
       end
     end
   end
+
 end

watir-common/unittests/setup/browser.rb

@@ -3,17 +3,14 @@
 case Watir.options[:browser]
 when 'ie'
   at_exit {Watir::IE.quit}
-
   $LOAD_PATH.unshift File.expand_path($watir_dev_lib)
-  require 'watir'
 
   speed = Watir.options[:speed].to_sym
   Watir::IE.speed = speed
   $browser = Watir::Browser.new
   $browser.speed = speed
 when 'firefox'
   $LOAD_PATH.unshift File.expand_path($firewatir_dev_lib)
-  require 'firewatir'
   $browser = Watir::Browser.new
 end
 

watir/lib/watir.rb

@@ -85,7 +85,7 @@
 require 'watir/collections'
 
 require 'watir/browser'
-Watir::Browser.module_eval "@@klass = Watir::IE"
+Watir.default_browser ||= 'ie' 
 
 module Watir
   include Watir::Exception