diff --git a/actionpack/lib/action_dispatch/middleware/show_exceptions.rb b/actionpack/lib/action_dispatch/middleware/show_exceptions.rb
index a765c23dae709..2fa68c64c54c1 100644
--- a/actionpack/lib/action_dispatch/middleware/show_exceptions.rb
+++ b/actionpack/lib/action_dispatch/middleware/show_exceptions.rb
@@ -86,8 +86,8 @@ def rescue_action_locally(request, exception)
           :framework_trace => framework_trace(exception),
           :full_trace => full_trace(exception)
         )
-        file = "rescues/#{@@rescue_templates[exception.class.name]}.erb"
-        body = template.render(:file => file, :layout => 'rescues/layout.erb')
+        file = "rescues/#{@@rescue_templates[exception.class.name]}"
+        body = template.render(:template => file, :layout => 'rescues/layout')
         render(status_code(exception), body)
       end
 
diff --git a/actionpack/lib/action_view/lookup_context.rb b/actionpack/lib/action_view/lookup_context.rb
index ef1ef44317218..fa4bf70f7733d 100644
--- a/actionpack/lib/action_view/lookup_context.rb
+++ b/actionpack/lib/action_view/lookup_context.rb
@@ -147,7 +147,12 @@ def detail_args_for(options)
       # as well as incorrectly putting part of the path in the template
       # name instead of the prefix.
       def normalize_name(name, prefixes) #:nodoc:
-        name  = name.to_s.gsub(handlers_regexp, '')
+        name  = name.to_s.sub(handlers_regexp) do |match|
+          ActiveSupport::Deprecation.warn "Passing a template handler in the template name is deprecated. " \
+            "You can simply remove the handler name or pass render :handlers => [:#{match[1..-1]}] instead.", caller
+          ""
+        end
+
         parts = name.split('/')
         name  = parts.pop
 
diff --git a/actionpack/lib/action_view/renderer/abstract_renderer.rb b/actionpack/lib/action_view/renderer/abstract_renderer.rb
index 24bae64ca5b3d..1656cf7ec767b 100644
--- a/actionpack/lib/action_view/renderer/abstract_renderer.rb
+++ b/actionpack/lib/action_view/renderer/abstract_renderer.rb
@@ -16,7 +16,7 @@ def render
     def extract_format(value, details)
       if value.is_a?(String) && value.sub!(formats_regexp, "")
         ActiveSupport::Deprecation.warn "Passing the format in the template name is deprecated. " \
-          "Please pass render with :formats => #{$1} instead.", caller
+          "Please pass render with :formats => [:#{$1}] instead.", caller
         details[:formats] ||= [$1.to_sym]
       end
     end
diff --git a/actionpack/test/abstract/abstract_controller_test.rb b/actionpack/test/abstract/abstract_controller_test.rb
index 5823e64637b19..bf068aedcd9a8 100644
--- a/actionpack/test/abstract/abstract_controller_test.rb
+++ b/actionpack/test/abstract/abstract_controller_test.rb
@@ -50,7 +50,7 @@ def index
       end
 
       def index_to_string
-        self.response_body = render_to_string "index.erb"
+        self.response_body = render_to_string "index"
       end
 
       def action_with_ivars
@@ -63,11 +63,11 @@ def naked_render
       end
 
       def rendering_to_body
-        self.response_body = render_to_body :template => "naked_render.erb"
+        self.response_body = render_to_body :template => "naked_render"
       end
 
       def rendering_to_string
-        self.response_body = render_to_string :template => "naked_render.erb"
+        self.response_body = render_to_string :template => "naked_render"
       end
     end
 
diff --git a/actionpack/test/controller/caching_test.rb b/actionpack/test/controller/caching_test.rb
index da3314fe6dee7..f3b180283facc 100644
--- a/actionpack/test/controller/caching_test.rb
+++ b/actionpack/test/controller/caching_test.rb
@@ -197,7 +197,7 @@ class ActionCachingTestController < CachingController
   caches_action :layout_false, :layout => false
   caches_action :record_not_found, :four_oh_four, :simple_runtime_error
 
-  layout 'talk_from_action.erb'
+  layout 'talk_from_action'
 
   def index
     @cache_this = MockTime.now.to_f.to_s
diff --git a/actionpack/test/controller/layout_test.rb b/actionpack/test/controller/layout_test.rb
index cafe2b9320d55..25299eb8b87d2 100644
--- a/actionpack/test/controller/layout_test.rb
+++ b/actionpack/test/controller/layout_test.rb
@@ -79,7 +79,7 @@ class DefaultLayoutController < LayoutTest
 end
 
 class AbsolutePathLayoutController < LayoutTest
-  layout File.expand_path(File.expand_path(__FILE__) + '/../../fixtures/layout_tests/layouts/layout_test.erb')
+  layout File.expand_path(File.expand_path(__FILE__) + '/../../fixtures/layout_tests/layouts/layout_test')
 end
 
 class HasOwnLayoutController < LayoutTest
@@ -184,7 +184,7 @@ def hello
 end
 
 class SetsNonExistentLayoutFile < LayoutTest
-  layout "nofile.erb"
+  layout "nofile"
 end
 
 class LayoutExceptionRaised < ActionController::TestCase
diff --git a/actionpack/test/controller/new_base/render_file_test.rb b/actionpack/test/controller/new_base/render_file_test.rb
index 8b2fdf8f96f3b..a961cbf849320 100644
--- a/actionpack/test/controller/new_base/render_file_test.rb
+++ b/actionpack/test/controller/new_base/render_file_test.rb
@@ -10,7 +10,7 @@ def index
 
     def with_instance_variables
       @secret = 'in the sauce'
-      render :file => File.join(File.dirname(__FILE__), '../../fixtures/test/render_file_with_ivar.erb')
+      render :file => File.join(File.dirname(__FILE__), '../../fixtures/test/render_file_with_ivar')
     end
 
     def without_file_key
@@ -19,7 +19,7 @@ def without_file_key
 
     def without_file_key_with_instance_variable
       @secret = 'in the sauce'
-      render File.join(File.dirname(__FILE__), '../../fixtures/test/render_file_with_ivar.erb')
+      render File.join(File.dirname(__FILE__), '../../fixtures/test/render_file_with_ivar')
     end
 
     def relative_path
@@ -34,16 +34,16 @@ def relative_path_with_dot
 
     def pathname
       @secret = 'in the sauce'
-      render :file => Pathname.new(File.dirname(__FILE__)).join(*%w[.. .. fixtures test dot.directory render_file_with_ivar.erb])
+      render :file => Pathname.new(File.dirname(__FILE__)).join(*%w[.. .. fixtures test dot.directory render_file_with_ivar])
     end
 
     def with_locals
-      path = File.join(File.dirname(__FILE__), '../../fixtures/test/render_file_with_locals.erb')
+      path = File.join(File.dirname(__FILE__), '../../fixtures/test/render_file_with_locals')
       render :file => path, :locals => {:secret => 'in the sauce'}
     end
 
     def without_file_key_with_locals
-      path = FIXTURES.join('test/render_file_with_locals.erb').to_s
+      path = FIXTURES.join('test/render_file_with_locals').to_s
       render path, :locals => {:secret => 'in the sauce'}
     end
   end
diff --git a/actionpack/test/controller/render_test.rb b/actionpack/test/controller/render_test.rb
index 719e37799d681..aea603b0143dc 100644
--- a/actionpack/test/controller/render_test.rb
+++ b/actionpack/test/controller/render_test.rb
@@ -163,14 +163,14 @@ def hello_world_with_layout_false
   # :ported:
   def render_file_with_instance_variables
     @secret = 'in the sauce'
-    path = File.join(File.dirname(__FILE__), '../fixtures/test/render_file_with_ivar.erb')
+    path = File.join(File.dirname(__FILE__), '../fixtures/test/render_file_with_ivar')
     render :file => path
   end
 
   # :ported:
   def render_file_as_string_with_instance_variables
     @secret = 'in the sauce'
-    path = File.expand_path(File.join(File.dirname(__FILE__), '../fixtures/test/render_file_with_ivar.erb'))
+    path = File.expand_path(File.join(File.dirname(__FILE__), '../fixtures/test/render_file_with_ivar'))
     render path
   end
 
@@ -187,21 +187,21 @@ def render_file_not_using_full_path_with_dot_in_path
 
   def render_file_using_pathname
     @secret = 'in the sauce'
-    render :file => Pathname.new(File.dirname(__FILE__)).join('..', 'fixtures', 'test', 'dot.directory', 'render_file_with_ivar.erb')
+    render :file => Pathname.new(File.dirname(__FILE__)).join('..', 'fixtures', 'test', 'dot.directory', 'render_file_with_ivar')
   end
 
   def render_file_from_template
     @secret = 'in the sauce'
-    @path = File.expand_path(File.join(File.dirname(__FILE__), '../fixtures/test/render_file_with_ivar.erb'))
+    @path = File.expand_path(File.join(File.dirname(__FILE__), '../fixtures/test/render_file_with_ivar'))
   end
 
   def render_file_with_locals
-    path = File.join(File.dirname(__FILE__), '../fixtures/test/render_file_with_locals.erb')
+    path = File.join(File.dirname(__FILE__), '../fixtures/test/render_file_with_locals')
     render :file => path, :locals => {:secret => 'in the sauce'}
   end
 
   def render_file_as_string_with_locals
-    path = File.expand_path(File.join(File.dirname(__FILE__), '../fixtures/test/render_file_with_locals.erb'))
+    path = File.expand_path(File.join(File.dirname(__FILE__), '../fixtures/test/render_file_with_locals'))
     render path, :locals => {:secret => 'in the sauce'}
   end
 
@@ -453,17 +453,13 @@ def rendering_with_conflicting_local_vars
     render :action => "potential_conflicts"
   end
 
-  # :deprecated:
-  # Tests being able to pick a .builder template over a .erb
-  # For instance, being able to have hello.xml.builder and hello.xml.erb
-  # and select one via "hello.builder" or "hello.erb"
   def hello_world_from_rxml_using_action
-    render :action => "hello_world_from_rxml.builder"
+    render :action => "hello_world_from_rxml", :handlers => [:builder]
   end
 
   # :deprecated:
   def hello_world_from_rxml_using_template
-    render :template => "test/hello_world_from_rxml.builder"
+    render :template => "test/hello_world_from_rxml", :handlers => [:builder]
   end
 
   def action_talk_to_layout
@@ -525,8 +521,8 @@ def render_using_layout_around_block_in_main_layout_and_within_content_for_layou
     render :action => "using_layout_around_block", :layout => "layouts/block_with_layout"
   end
 
-  def partial_dot_html
-    render :partial => 'partial.html.erb'
+  def partial_formats_html
+    render :partial => 'partial', :formats => [:html]
   end
 
   def partial
@@ -1235,8 +1231,8 @@ def test_should_render_html_formatted_partial
     assert_equal 'partial html', @response.body
   end
 
-  def test_should_render_html_partial_with_dot
-    get :partial_dot_html
+  def test_should_render_html_partial_with_formats
+    get :partial_formats_html
     assert_equal 'partial html', @response.body
   end
 
diff --git a/actionpack/test/fixtures/test/_layout_with_partial_and_yield.html.erb b/actionpack/test/fixtures/test/_layout_with_partial_and_yield.html.erb
index 5db0822f07c2a..820e7db789bfd 100644
--- a/actionpack/test/fixtures/test/_layout_with_partial_and_yield.html.erb
+++ b/actionpack/test/fixtures/test/_layout_with_partial_and_yield.html.erb
@@ -1,4 +1,4 @@
 Before
-<%= render :partial => "test/partial.html.erb" %>
+<%= render :partial => "test/partial" %>
 <%= yield %>
 After
diff --git a/actionpack/test/template/compiled_templates_test.rb b/actionpack/test/template/compiled_templates_test.rb
index 8be0f452fb780..8fc78283d8f2d 100644
--- a/actionpack/test/template/compiled_templates_test.rb
+++ b/actionpack/test/template/compiled_templates_test.rb
@@ -10,24 +10,24 @@ def setup
   end
 
   def test_template_gets_recompiled_when_using_different_keys_in_local_assigns
-    assert_equal "one", render(:file => "test/render_file_with_locals_and_default.erb")
-    assert_equal "two", render(:file => "test/render_file_with_locals_and_default.erb", :locals => { :secret => "two" })
+    assert_equal "one", render(:file => "test/render_file_with_locals_and_default")
+    assert_equal "two", render(:file => "test/render_file_with_locals_and_default", :locals => { :secret => "two" })
   end
 
   def test_template_changes_are_not_reflected_with_cached_templates
-    assert_equal "Hello world!", render(:file => "test/hello_world.erb")
+    assert_equal "Hello world!", render(:file => "test/hello_world")
     modify_template "test/hello_world.erb", "Goodbye world!" do
-      assert_equal "Hello world!", render(:file => "test/hello_world.erb")
+      assert_equal "Hello world!", render(:file => "test/hello_world")
     end
-    assert_equal "Hello world!", render(:file => "test/hello_world.erb")
+    assert_equal "Hello world!", render(:file => "test/hello_world")
   end
 
   def test_template_changes_are_reflected_with_uncached_templates
-    assert_equal "Hello world!", render_without_cache(:file => "test/hello_world.erb")
+    assert_equal "Hello world!", render_without_cache(:file => "test/hello_world")
     modify_template "test/hello_world.erb", "Goodbye world!" do
-      assert_equal "Goodbye world!", render_without_cache(:file => "test/hello_world.erb")
+      assert_equal "Goodbye world!", render_without_cache(:file => "test/hello_world")
     end
-    assert_equal "Hello world!", render_without_cache(:file => "test/hello_world.erb")
+    assert_equal "Hello world!", render_without_cache(:file => "test/hello_world")
   end
 
   private
diff --git a/actionpack/test/template/log_subscriber_test.rb b/actionpack/test/template/log_subscriber_test.rb
index 50e1cccd3b1c4..752b0f23a85d0 100644
--- a/actionpack/test/template/log_subscriber_test.rb
+++ b/actionpack/test/template/log_subscriber_test.rb
@@ -27,7 +27,7 @@ def set_logger(logger)
   end
 
   def test_render_file_template
-    @view.render(:file => "test/hello_world.erb")
+    @view.render(:file => "test/hello_world")
     wait
 
     assert_equal 1, @logger.logged(:info).size
diff --git a/actionpack/test/template/render_test.rb b/actionpack/test/template/render_test.rb
index f3dce0b7f2b50..120f91b0e7c7c 100644
--- a/actionpack/test/template/render_test.rb
+++ b/actionpack/test/template/render_test.rb
@@ -21,11 +21,11 @@ def setup_view(paths)
   end
 
   def test_render_file
-    assert_equal "Hello world!", @view.render(:file => "test/hello_world.erb")
+    assert_equal "Hello world!", @view.render(:file => "test/hello_world")
   end
 
   def test_render_file_not_using_full_path
-    assert_equal "Hello world!", @view.render(:file => "test/hello_world.erb")
+    assert_equal "Hello world!", @view.render(:file => "test/hello_world")
   end
 
   def test_render_file_without_specific_extension
@@ -62,17 +62,17 @@ def test_render_file_at_top_level
   end
 
   def test_render_file_with_full_path
-    template_path = File.join(File.dirname(__FILE__), '../fixtures/test/hello_world.erb')
+    template_path = File.join(File.dirname(__FILE__), '../fixtures/test/hello_world')
     assert_equal "Hello world!", @view.render(:file => template_path)
   end
 
   def test_render_file_with_instance_variables
-    assert_equal "The secret is in the sauce\n", @view.render(:file => "test/render_file_with_ivar.erb")
+    assert_equal "The secret is in the sauce\n", @view.render(:file => "test/render_file_with_ivar")
   end
 
   def test_render_file_with_locals
     locals = { :secret => 'in the sauce' }
-    assert_equal "The secret is in the sauce\n", @view.render(:file => "test/render_file_with_locals.erb", :locals => locals)
+    assert_equal "The secret is in the sauce\n", @view.render(:file => "test/render_file_with_locals", :locals => locals)
   end
 
   def test_render_file_not_using_full_path_with_dot_in_path
@@ -92,12 +92,12 @@ def test_render_partial_with_format
   end
 
   def test_render_partial_at_top_level
-    # file fixtures/_top_level_partial_only.erb (not fixtures/test)
+    # file fixtures/_top_level_partial_only (not fixtures/test)
     assert_equal 'top level partial', @view.render(:partial => '/top_level_partial_only')
   end
 
   def test_render_partial_with_format_at_top_level
-    # file fixtures/_top_level_partial.html.erb (not fixtures/test, with format extension)
+    # file fixtures/_top_level_partial.html (not fixtures/test, with format extension)
     assert_equal 'top level partial html', @view.render(:partial => '/top_level_partial')
   end
 
@@ -256,7 +256,7 @@ def test_render_missing_xml_partial_and_raise_missing_template
   end
 
   def test_render_layout_with_block_and_other_partial_inside
-    render = @view.render(:layout => "test/layout_with_partial_and_yield.html.erb") { "Yield!" }
+    render = @view.render(:layout => "test/layout_with_partial_and_yield") { "Yield!" }
     assert_equal "Before\npartial html\nYield!\nAfter\n", render
   end
 
@@ -293,24 +293,26 @@ def test_render_inline_with_locals_and_compilable_custom_type
   end
 
   def test_render_ignores_templates_with_malformed_template_handlers
-    %w(malformed malformed.erb malformed.html.erb malformed.en.html.erb).each do |name|
-      assert_raise(ActionView::MissingTemplate) { @view.render(:file => "test/malformed/#{name}") }
+    ActiveSupport::Deprecation.silence do
+      %w(malformed malformed.erb malformed.html.erb malformed.en.html.erb).each do |name|
+        assert_raise(ActionView::MissingTemplate) { @view.render(:file => "test/malformed/#{name}") }
+      end
     end
   end
 
   def test_render_with_layout
     assert_equal %(<title></title>\nHello world!\n),
-      @view.render(:file => "test/hello_world.erb", :layout => "layouts/yield")
+      @view.render(:file => "test/hello_world", :layout => "layouts/yield")
   end
 
   def test_render_with_layout_which_has_render_inline
     assert_equal %(welcome\nHello world!\n),
-      @view.render(:file => "test/hello_world.erb", :layout => "layouts/yield_with_render_inline_inside")
+      @view.render(:file => "test/hello_world", :layout => "layouts/yield_with_render_inline_inside")
   end
 
   def test_render_with_layout_which_renders_another_partial
     assert_equal %(partial html\nHello world!\n),
-      @view.render(:file => "test/hello_world.erb", :layout => "layouts/yield_with_render_partial_inside")
+      @view.render(:file => "test/hello_world", :layout => "layouts/yield_with_render_partial_inside")
   end
 
   def test_render_layout_with_block_and_yield
@@ -355,17 +357,17 @@ def test_render_layout_with_a_nested_render_layout_call_using_block_with_render_
 
   def test_render_with_nested_layout
     assert_equal %(<title>title</title>\n\n<div id="column">column</div>\n<div id="content">content</div>\n),
-      @view.render(:file => "test/nested_layout.erb", :layout => "layouts/yield")
+      @view.render(:file => "test/nested_layout", :layout => "layouts/yield")
   end
 
   def test_render_with_file_in_layout
     assert_equal %(\n<title>title</title>\n\n),
-      @view.render(:file => "test/layout_render_file.erb")
+      @view.render(:file => "test/layout_render_file")
   end
 
   def test_render_layout_with_object
     assert_equal %(<title>David</title>),
-      @view.render(:file => "test/layout_render_object.erb")
+      @view.render(:file => "test/layout_render_object")
   end
 end
 
@@ -403,7 +405,7 @@ def teardown
   if '1.9'.respond_to?(:force_encoding)
     def test_render_utf8_template_with_magic_comment
       with_external_encoding Encoding::ASCII_8BIT do
-        result = @view.render(:file => "test/utf8_magic.html.erb", :layouts => "layouts/yield")
+        result = @view.render(:file => "test/utf8_magic.html", :layouts => "layouts/yield")
         assert_equal Encoding::UTF_8, result.encoding
         assert_equal "\nРусский \nтекст\n\nUTF-8\nUTF-8\nUTF-8\n", result
       end
@@ -411,7 +413,7 @@ def test_render_utf8_template_with_magic_comment
 
     def test_render_utf8_template_with_default_external_encoding
       with_external_encoding Encoding::UTF_8 do
-        result = @view.render(:file => "test/utf8.html.erb", :layouts => "layouts/yield")
+        result = @view.render(:file => "test/utf8.html", :layouts => "layouts/yield")
         assert_equal Encoding::UTF_8, result.encoding
         assert_equal "Русский текст\n\nUTF-8\nUTF-8\nUTF-8\n", result
       end
@@ -420,7 +422,7 @@ def test_render_utf8_template_with_default_external_encoding
     def test_render_utf8_template_with_incompatible_external_encoding
       with_external_encoding Encoding::SHIFT_JIS do
         begin
-          @view.render(:file => "test/utf8.html.erb", :layouts => "layouts/yield")
+          @view.render(:file => "test/utf8.html", :layouts => "layouts/yield")
           flunk 'Should have raised incompatible encoding error'
         rescue ActionView::Template::Error => error
           assert_match 'Your template was not saved as valid Shift_JIS', error.original_exception.message
@@ -431,7 +433,7 @@ def test_render_utf8_template_with_incompatible_external_encoding
     def test_render_utf8_template_with_partial_with_incompatible_encoding
       with_external_encoding Encoding::SHIFT_JIS do
         begin
-          @view.render(:file => "test/utf8_magic_with_bare_partial.html.erb", :layouts => "layouts/yield")
+          @view.render(:file => "test/utf8_magic_with_bare_partial.html", :layouts => "layouts/yield")
           flunk 'Should have raised incompatible encoding error'
         rescue ActionView::Template::Error => error
           assert_match 'Your template was not saved as valid Shift_JIS', error.original_exception.message
diff --git a/actionpack/test/template/streaming_render_test.rb b/actionpack/test/template/streaming_render_test.rb
index 023ce723ed117..4d01352b43b4e 100644
--- a/actionpack/test/template/streaming_render_test.rb
+++ b/actionpack/test/template/streaming_render_test.rb
@@ -28,7 +28,7 @@ def buffered_render(options)
 
   def test_streaming_works
     content = []
-    body = render_body(:template => "test/hello_world.erb", :layout => "layouts/yield")
+    body = render_body(:template => "test/hello_world", :layout => "layouts/yield")
 
     body.each do |piece|
       content << piece
@@ -42,12 +42,12 @@ def test_streaming_works
   end
 
   def test_render_file
-    assert_equal "Hello world!", buffered_render(:file => "test/hello_world.erb")
+    assert_equal "Hello world!", buffered_render(:file => "test/hello_world")
   end
 
   def test_render_file_with_locals
     locals = { :secret => 'in the sauce' }
-    assert_equal "The secret is in the sauce\n", buffered_render(:file => "test/render_file_with_locals.erb", :locals => locals)
+    assert_equal "The secret is in the sauce\n", buffered_render(:file => "test/render_file_with_locals", :locals => locals)
   end
 
   def test_render_partial
@@ -64,27 +64,27 @@ def test_render_without_layout
 
   def test_render_with_layout
     assert_equal %(<title></title>\nHello world!\n),
-      buffered_render(:template => "test/hello_world.erb", :layout => "layouts/yield")
+      buffered_render(:template => "test/hello_world", :layout => "layouts/yield")
   end
 
   def test_render_with_layout_which_has_render_inline
     assert_equal %(welcome\nHello world!\n),
-      buffered_render(:template => "test/hello_world.erb", :layout => "layouts/yield_with_render_inline_inside")
+      buffered_render(:template => "test/hello_world", :layout => "layouts/yield_with_render_inline_inside")
   end
 
   def test_render_with_layout_which_renders_another_partial
     assert_equal %(partial html\nHello world!\n),
-      buffered_render(:template => "test/hello_world.erb", :layout => "layouts/yield_with_render_partial_inside")
+      buffered_render(:template => "test/hello_world", :layout => "layouts/yield_with_render_partial_inside")
   end
 
   def test_render_with_nested_layout
     assert_equal %(<title>title</title>\n\n<div id="column">column</div>\n<div id="content">content</div>\n),
-      buffered_render(:template => "test/nested_layout.erb", :layout => "layouts/yield")
+      buffered_render(:template => "test/nested_layout", :layout => "layouts/yield")
   end
 
   def test_render_with_file_in_layout
     assert_equal %(\n<title>title</title>\n\n),
-      buffered_render(:template => "test/layout_render_file.erb")
+      buffered_render(:template => "test/layout_render_file")
   end
 
   def test_render_with_handler_without_streaming_support