diff --git a/README.de.rdoc b/README.de.rdoc
index 7b7e9eee..bd4dd2eb 100644
--- a/README.de.rdoc
+++ b/README.de.rdoc
@@ -229,7 +229,6 @@ Das buidler gem wird benötigt, um Builder-Templates rendern zu können:
   require 'builder'
 
   get '/' do
-    content_type 'application/xml', :charset => 'utf-8'
     builder :index
   end
 
@@ -243,7 +242,6 @@ Das haml gem wird benötigt, um SASS-Templates rendern zu können:
   require 'sass'
 
   get '/stylesheet.css' do
-    content_type 'text/css', :charset => 'utf-8'
     sass :stylesheet
   end
 
@@ -257,7 +255,6 @@ und individuell überschrieben werden.
   set :sass, :style => :compact # Standard Sass-Style ist :nested
 
   get '/stylesheet.css' do
-    content_type 'text/css', :charset => 'utf-8'
     sass :stylesheet, :style => :expanded # überschrieben
   end
 
@@ -269,7 +266,6 @@ Das haml gem wird benötigt, um SCSS-Templates rendern zu können:
   require 'sass'
 
   get '/stylesheet.css' do
-    content_type 'text/css', :charset => 'utf-8'
     scss :stylesheet
   end
 
@@ -283,7 +279,6 @@ und individuell überschrieben werden.
   set :scss, :style => :compact # Standard Scss-Style ist :nested
 
   get '/stylesheet.css' do
-    content_type 'text/css', :charset => 'utf-8'
     scss :stylesheet, :style => :expanded # überschrieben
   end
 
@@ -295,7 +290,6 @@ Das less gem wird benötigt, um Less-Templates rendern zu können:
   require 'less'
 
   get '/stylesheet.css' do
-    content_type 'text/css', :charset => 'utf-8'
     less :stylesheet
   end
 
@@ -434,7 +428,6 @@ Das coffee-script gem und das `coffee`-Programm werden benötigt, um CoffeScript
   require 'coffee-script'
 
   get '/application.js' do
-    content_type 'text/javascript', :charset => 'utf-8'
     coffee :application
   end
 
diff --git a/README.jp.rdoc b/README.jp.rdoc
index ad8250a1..7cf6bbe3 100644
--- a/README.jp.rdoc
+++ b/README.jp.rdoc
@@ -154,7 +154,6 @@ builderを使うにはbuilderライブラリが必要です:
   require 'builder'
 
   get '/' do
-    content_type 'application/xml', :charset => 'utf-8'
     builder :index
   end
 
@@ -168,7 +167,6 @@ Sassテンプレートを使うにはsassライブラリが必要です:
   require 'sass'
 
   get '/stylesheet.css' do
-    content_type 'text/css', :charset => 'utf-8'
     sass :stylesheet
   end
 
@@ -182,7 +180,6 @@ see {Options and Configurations}[http://www.sinatrarb.com/configuration.html],
   set :sass, {:style => :compact } # デフォルトのSass styleは :nested
 
   get '/stylesheet.css' do
-    content_type 'text/css', :charset => 'utf-8'
     sass :stylesheet, :sass_options => {:style => :expanded } # 上書き
   end
 
diff --git a/README.rdoc b/README.rdoc
index d7562884..0117c3d4 100644
--- a/README.rdoc
+++ b/README.rdoc
@@ -225,7 +225,6 @@ The builder gem/library is required to render builder templates:
   require 'builder'
 
   get '/' do
-    content_type 'application/xml', :charset => 'utf-8'
     builder :index
   end
 
@@ -239,7 +238,6 @@ The sass gem/library is required to render Sass templates:
   require 'sass'
 
   get '/stylesheet.css' do
-    content_type 'text/css', :charset => 'utf-8'
     sass :stylesheet
   end
 
@@ -253,7 +251,6 @@ and overridden on an individual basis.
   set :sass, :style => :compact # default Sass style is :nested
 
   get '/stylesheet.css' do
-    content_type 'text/css', :charset => 'utf-8'
     sass :stylesheet, :style => :expanded # overridden
   end
 
@@ -265,7 +262,6 @@ The sass gem/library is required to render Scss templates:
   require 'sass'
 
   get '/stylesheet.css' do
-    content_type 'text/css', :charset => 'utf-8'
     scss :stylesheet
   end
 
@@ -279,7 +275,6 @@ and overridden on an individual basis.
   set :scss, :style => :compact # default Scss style is :nested
 
   get '/stylesheet.css' do
-    content_type 'text/css', :charset => 'utf-8'
     scss :stylesheet, :style => :expanded # overridden
   end
 
@@ -291,7 +286,6 @@ The less gem/library is required to render Less templates:
   require 'less'
 
   get '/stylesheet.css' do
-    content_type 'text/css', :charset => 'utf-8'
     less :stylesheet
   end
 
@@ -422,7 +416,6 @@ CoffeeScript templates:
   require 'coffee-script'
 
   get '/application.js' do
-    content_type 'text/javascript', :charset => 'utf-8'
     coffee :application
   end
 
diff --git a/lib/sinatra/base.rb b/lib/sinatra/base.rb
index 609b7f28..b33c85db 100644
--- a/lib/sinatra/base.rb
+++ b/lib/sinatra/base.rb
@@ -77,10 +77,12 @@ module Sinatra
     # evaluation is deferred until the body is read with #each.
     def body(value=nil, &block)
       if block_given?
-        def block.each ; yield call ; end
+        def block.each; yield(call) end
         response.body = block
-      else
+      elsif value
         response.body = value
+      else
+        response.body
       end
     end
 
@@ -137,6 +139,7 @@ module Sinatra
     def content_type(type, params={})
       mime_type = mime_type(type)
       fail "Unknown media type: %p" % type if mime_type.nil?
+      params[:charset] ||= defined?(Encoding) ? Encoding.default_external.to_s.downcase : 'utf-8'
       if params.any?
         params = params.collect { |kv| "%s=%s" % kv }.join(', ')
         response['Content-Type'] = [mime_type, params].join(";")
@@ -303,6 +306,10 @@ module Sinatra
   #   :locals       A hash with local variables that should be available
   #                 in the template
   module Templates
+    module ContentTyped
+      attr_accessor :content_type
+    end
+
     include Tilt::CompileSite
 
     def erb(template, options={}, locals={})
@@ -318,21 +325,22 @@ module Sinatra
     end
 
     def sass(template, options={}, locals={})
-      options[:layout] = false
+      options.merge! :layout => false, :default_content_type => :css
       render :sass, template, options, locals
     end
 
     def scss(template, options={}, locals={})
-      options[:layout] = false
+      options.merge! :layout => false, :default_content_type => :css
       render :scss, template, options, locals
     end
 
     def less(template, options={}, locals={})
-      options[:layout] = false
+      options.merge! :layout => false, :default_content_type => :css
       render :less, template, options, locals
     end
 
     def builder(template=nil, options={}, locals={}, &block)
+      options[:default_content_type] = :xml
       options, template = template, nil if template.is_a?(Hash)
       template = Proc.new { block } if template.nil?
       render :builder, template, options, locals
@@ -363,7 +371,7 @@ module Sinatra
     end
 
     def coffee(template, options={}, locals={})
-      options[:layout] = false
+      options.merge! :layout => false, :default_content_type => :js
       render :coffee, template, options, locals
     end
 
@@ -374,14 +382,19 @@ module Sinatra
       options[:outvar] ||= '@_out_buf'
 
       # extract generic options
-      locals = options.delete(:locals) || locals || {}
-      views = options.delete(:views) || settings.views || "./views"
-      layout = options.delete(:layout)
-      layout = :layout if layout.nil? || layout == true
+      locals          = options.delete(:locals) || locals         || {}
+      views           = options.delete(:views)  || settings.views || "./views"
+      @default_layout = :layout if @default_layout.nil?
+      layout          = options.delete(:layout)
+      layout          = @default_layout if layout.nil? or layout == true
+      content_type    = options.delete(:content_type) || options.delete(:default_content_type)
 
       # compile and render template
-      template = compile_template(engine, data, options, views)
-      output = template.render(self, locals, &block)
+      layout_was      = @default_layout
+      @default_layout = false if layout
+      template        = compile_template(engine, data, options, views)
+      output          = template.render(self, locals, &block)
+      @default_layout = layout_was
 
       # render layout
       if layout
@@ -392,6 +405,7 @@ module Sinatra
         end
       end
 
+      output.extend(ContentTyped).content_type = content_type if content_type
       output
     end
 
@@ -456,8 +470,16 @@ module Sinatra
       template_cache.clear if settings.reload_templates
       force_encoding(@params)
 
+      @response['Content-Type'] = nil
       invoke { dispatch! }
       invoke { error_block!(response.status) }
+      unless @response['Content-Type']
+        if body.respond_to?(:to_ary) and body.first.respond_to? :content_type
+          content_type body.first.content_type
+        else
+          content_type :html
+        end
+      end
 
       status, header, body = @response.finish
 
diff --git a/test/builder_test.rb b/test/builder_test.rb
index 04ab3a58..92a0ffe3 100644
--- a/test/builder_test.rb
+++ b/test/builder_test.rb
@@ -2,9 +2,10 @@ require File.dirname(__FILE__) + '/helper'
 require 'builder'
 
 class BuilderTest < Test::Unit::TestCase
-  def builder_app(&block)
+  def builder_app(options = {}, &block)
     mock_app {
       set :views, File.dirname(__FILE__) + '/views'
+      set options
       get '/', &block
     }
     get '/'
@@ -16,6 +17,29 @@ class BuilderTest < Test::Unit::TestCase
     assert_equal %{<?xml version="1.0" encoding="UTF-8"?>\n}, body
   end
 
+  it 'defaults content type to xml' do
+    builder_app { builder 'xml.instruct!' }
+    assert ok?
+    assert_equal "application/xml;charset=utf-8", response['Content-Type']
+  end
+
+  it 'defaults allows setting content type per route' do
+    builder_app do
+      content_type :html
+      builder 'xml.instruct!'
+    end
+    assert ok?
+    assert_equal "text/html;charset=utf-8", response['Content-Type']
+  end
+
+  it 'defaults allows setting content type globally' do
+    builder_app(:builder => { :content_type => 'html' }) do
+      builder 'xml.instruct!'
+    end
+    assert ok?
+    assert_equal "text/html;charset=utf-8", response['Content-Type']
+  end
+
   it 'renders inline blocks' do
     builder_app {
       @name = "Frank & Mary"
diff --git a/test/coffee_test.rb b/test/coffee_test.rb
index c71f9d25..f9677ae7 100644
--- a/test/coffee_test.rb
+++ b/test/coffee_test.rb
@@ -4,9 +4,10 @@ begin
 require 'coffee-script'
 
 class CoffeeTest < Test::Unit::TestCase
-  def coffee_app(&block)
+  def coffee_app(options = {}, &block)
     mock_app {
       set :views, File.dirname(__FILE__) + '/views'
+      set(options)
       get '/', &block
     }
     get '/'
@@ -18,6 +19,29 @@ class CoffeeTest < Test::Unit::TestCase
     assert_equal "(function() {\n  alert('Aye!');\n})();\n", body
   end
 
+  it 'defaults content type to javascript' do
+    coffee_app { coffee "alert 'Aye!'\n" }
+    assert ok?
+    assert_equal "application/javascript;charset=utf-8", response['Content-Type']
+  end
+
+  it 'defaults allows setting content type per route' do
+    coffee_app do
+      content_type :html
+      coffee "alert 'Aye!'\n"
+    end
+    assert ok?
+    assert_equal "text/html;charset=utf-8", response['Content-Type']
+  end
+
+  it 'defaults allows setting content type globally' do
+    coffee_app(:coffee => { :content_type => 'html' }) do
+      coffee "alert 'Aye!'\n"
+    end
+    assert ok?
+    assert_equal "text/html;charset=utf-8", response['Content-Type']
+  end
+
   it 'renders .coffee files in views path' do
     coffee_app { coffee :hello }
     assert ok?
diff --git a/test/helper.rb b/test/helper.rb
index 70699295..2220ebca 100644
--- a/test/helper.rb
+++ b/test/helper.rb
@@ -1,4 +1,5 @@
 ENV['RACK_ENV'] = 'test'
+Encoding.default_external = "UTF-8" if defined? Encoding
 
 begin
   require 'rack'
diff --git a/test/helpers_test.rb b/test/helpers_test.rb
index b87a2e7f..b0b6d076 100644
--- a/test/helpers_test.rb
+++ b/test/helpers_test.rb
@@ -291,21 +291,21 @@ class HelpersTest < Test::Unit::TestCase
       }
 
       get '/'
-      assert_equal 'text/plain', response['Content-Type']
+      assert_equal 'text/plain;charset=utf-8', response['Content-Type']
       assert_equal 'Hello World', body
     end
 
     it 'takes media type parameters (like charset=)' do
       mock_app {
         get '/' do
-          content_type 'text/html', :charset => 'utf-8'
+          content_type 'text/html', :charset => 'latin1'
           "<h1>Hello, World</h1>"
         end
       }
 
       get '/'
       assert ok?
-      assert_equal 'text/html;charset=utf-8', response['Content-Type']
+      assert_equal 'text/html;charset=latin1', response['Content-Type']
       assert_equal "<h1>Hello, World</h1>", body
     end
 
@@ -320,7 +320,7 @@ class HelpersTest < Test::Unit::TestCase
 
       get '/foo.xml'
       assert ok?
-      assert_equal 'application/foo', response['Content-Type']
+      assert_equal 'application/foo;charset=utf-8', response['Content-Type']
       assert_equal 'I AM FOO', body
     end
 
@@ -366,19 +366,19 @@ class HelpersTest < Test::Unit::TestCase
     it 'sets the Content-Type response header if a mime-type can be located' do
       send_file_app
       get '/file.txt'
-      assert_equal 'text/plain', response['Content-Type']
+      assert_equal 'text/plain;charset=utf-8', response['Content-Type']
     end
 
     it 'sets the Content-Type response header if type option is set to a file extesion' do
       send_file_app :type => 'html'
       get '/file.txt'
-      assert_equal 'text/html', response['Content-Type']
+      assert_equal 'text/html;charset=utf-8', response['Content-Type']
     end
 
     it 'sets the Content-Type response header if type option is set to a mime type' do
       send_file_app :type => 'application/octet-stream'
       get '/file.txt'
-      assert_equal 'application/octet-stream', response['Content-Type']
+      assert_equal 'application/octet-stream;charset=utf-8', response['Content-Type']
     end
 
     it 'sets the Content-Length response header' do
diff --git a/test/less_test.rb b/test/less_test.rb
index f6cd72fd..ef9ac158 100644
--- a/test/less_test.rb
+++ b/test/less_test.rb
@@ -2,20 +2,44 @@ require File.dirname(__FILE__) + '/helper'
 require 'less'
 
 class LessTest < Test::Unit::TestCase
-  def less_app(&block)
+  def less_app(options = {}, &block)
     mock_app {
       set :views, File.dirname(__FILE__) + '/views'
+      set options
       get '/', &block
     }
     get '/'
   end
 
   it 'renders inline Less strings' do
-    less_app { less "@white_color: #fff; #main { background-color: @white_color }"}
+    less_app { less "@white_color: #fff; #main { background-color: @white_color }" }
     assert ok?
     assert_equal "#main { background-color: #ffffff; }\n", body
   end
 
+  it 'defaults content type to css' do
+    less_app { less "@white_color: #fff; #main { background-color: @white_color }" }
+    assert ok?
+    assert_equal "text/css;charset=utf-8", response['Content-Type']
+  end
+
+  it 'defaults allows setting content type per route' do
+    less_app do
+      content_type :html
+      less "@white_color: #fff; #main { background-color: @white_color }"
+    end
+    assert ok?
+    assert_equal "text/html;charset=utf-8", response['Content-Type']
+  end
+
+  it 'defaults allows setting content type globally' do
+    less_app(:less => { :content_type => 'html' }) do
+      less "@white_color: #fff; #main { background-color: @white_color }"
+    end
+    assert ok?
+    assert_equal "text/html;charset=utf-8", response['Content-Type']
+  end
+
   it 'renders .less files in views path' do
     less_app { less :hello }
     assert ok?
diff --git a/test/routing_test.rb b/test/routing_test.rb
index 956f5b64..85961a55 100644
--- a/test/routing_test.rb
+++ b/test/routing_test.rb
@@ -80,7 +80,7 @@ class RoutingTest < Test::Unit::TestCase
 
     get '/foo'
     assert_equal 404, status
-    assert_equal 'text/html', response["Content-Type"]
+    assert_equal 'text/html;charset=utf-8', response["Content-Type"]
     assert_equal "<h1>Not Found</h1>", response.body
   end
 
diff --git a/test/sass_test.rb b/test/sass_test.rb
index 596e3c45..e1a24329 100644
--- a/test/sass_test.rb
+++ b/test/sass_test.rb
@@ -4,9 +4,10 @@ begin
 require 'sass'
 
 class SassTest < Test::Unit::TestCase
-  def sass_app(&block)
+  def sass_app(options = {}, &block)
     mock_app {
       set :views, File.dirname(__FILE__) + '/views'
+      set options
       get '/', &block
     }
     get '/'
@@ -18,6 +19,29 @@ class SassTest < Test::Unit::TestCase
     assert_equal "#sass {\n  background-color: white; }\n", body
   end
 
+  it 'defaults content type to css' do
+    sass_app { sass "#sass\n  :background-color white\n" }
+    assert ok?
+    assert_equal "text/css;charset=utf-8", response['Content-Type']
+  end
+
+  it 'defaults allows setting content type per route' do
+    sass_app do
+      content_type :html
+      sass "#sass\n  :background-color white\n"
+    end
+    assert ok?
+    assert_equal "text/html;charset=utf-8", response['Content-Type']
+  end
+
+  it 'defaults allows setting content type globally' do
+    sass_app(:sass => { :content_type => 'html' }) do
+      sass "#sass\n  :background-color white\n"
+    end
+    assert ok?
+    assert_equal "text/html;charset=utf-8", response['Content-Type']
+  end
+
   it 'renders .sass files in views path' do
     sass_app { sass :hello }
     assert ok?
diff --git a/test/scss_test.rb b/test/scss_test.rb
index 7fccb8f2..d1df4919 100644
--- a/test/scss_test.rb
+++ b/test/scss_test.rb
@@ -4,9 +4,10 @@ begin
 require 'sass'
 
 class ScssTest < Test::Unit::TestCase
-  def scss_app(&block)
+  def scss_app(options = {}, &block)
     mock_app {
       set :views, File.dirname(__FILE__) + '/views'
+      set options
       get '/', &block
     }
     get '/'
@@ -18,6 +19,29 @@ class ScssTest < Test::Unit::TestCase
     assert_equal "#scss {\n  background-color: white; }\n", body
   end
 
+  it 'defaults content type to css' do
+    scss_app { scss "#scss {\n  background-color: white; }\n" }
+    assert ok?
+    assert_equal "text/css;charset=utf-8", response['Content-Type']
+  end
+
+  it 'defaults allows setting content type per route' do
+    scss_app do
+      content_type :html
+      scss "#scss {\n  background-color: white; }\n"
+    end
+    assert ok?
+    assert_equal "text/html;charset=utf-8", response['Content-Type']
+  end
+
+  it 'defaults allows setting content type globally' do
+    scss_app(:scss => { :content_type => 'html' }) do
+      scss "#scss {\n  background-color: white; }\n"
+    end
+    assert ok?
+    assert_equal "text/html;charset=utf-8", response['Content-Type']
+  end
+
   it 'renders .scss files in views path' do
     scss_app { scss :hello }
     assert ok?
diff --git a/test/templates_test.rb b/test/templates_test.rb
index 3eb7fd34..48f0ec65 100644
--- a/test/templates_test.rb
+++ b/test/templates_test.rb
@@ -15,9 +15,11 @@ class TestTemplate < Tilt::Template
 end
 
 class TemplatesTest < Test::Unit::TestCase
-  def render_app(base=Sinatra::Base, &block)
+  def render_app(base=Sinatra::Base, options = {}, &block)
+    base, options = Sinatra::Base, base if base.is_a? Hash
     mock_app(base) {
       set :views, File.dirname(__FILE__) + '/views'
+      set options
       get '/', &block
       template(:layout3) { "Layout 3!\n" }
     }
@@ -78,6 +80,27 @@ class TemplatesTest < Test::Unit::TestCase
     assert_equal "Layout 3!\nHello World!\n", body
   end
 
+  it 'avoids wrapping layouts around nested templates' do
+    render_app { render :str, :nested, :layout => :layout2 }
+    assert ok?
+    assert_equal "<h1>String Layout!</h1>\n<content><h1>Hello From String</h1></content>", body
+  end
+
+  it 'allows explicitly wrapping layouts around nested templates' do
+    render_app { render :str, :explicitly_nested, :layout => :layout2 }
+    assert ok?
+    assert_equal "<h1>String Layout!</h1>\n<content><h1>String Layout!</h1>\n<h1>Hello From String</h1></content>", body
+  end
+
+  it 'two independent render calls do not disable layouts' do
+    render_app do
+      render :str, :explicitly_nested, :layout => :layout2
+      render :str, :nested, :layout => :layout2
+    end
+    assert ok?
+    assert_equal "<h1>String Layout!</h1>\n<content><h1>Hello From String</h1></content>", body
+  end
+
   it 'loads templates from source file' do
     mock_app { enable :inline_templates }
     assert_equal "this is foo\n\n", @app.templates[:foo][0]
@@ -135,6 +158,24 @@ class TemplatesTest < Test::Unit::TestCase
     assert_equal 'bar', body
   end
 
+  it 'allows setting default content type per template engine' do
+    render_app(:str => { :content_type => :txt }) { render :str, 'foo' }
+    assert_equal 'text/plain;charset=utf-8', response['Content-Type']
+  end
+
+  it 'setting default content type does not affect other template engines' do
+    render_app(:str => { :content_type => :txt }) { render :test, 'foo' }
+    assert_equal 'text/html;charset=utf-8', response['Content-Type']
+  end
+
+  it 'setting default content type per template engine does not override content_type' do
+    render_app :str => { :content_type => :txt } do
+      content_type :html
+      render :str, 'foo'
+    end
+    assert_equal 'text/html;charset=utf-8', response['Content-Type']
+  end
+
   it 'uses templates in superclasses before subclasses' do
     base = Class.new(Sinatra::Base)
     base.template(:foo) { 'template in superclass' }
diff --git a/test/views/explicitly_nested.str b/test/views/explicitly_nested.str
new file mode 100644
index 00000000..a3b0875b
--- /dev/null
+++ b/test/views/explicitly_nested.str
@@ -0,0 +1 @@
+<content>#{render :str, :hello, :layout => :layout2}</content>
\ No newline at end of file
diff --git a/test/views/hello.str b/test/views/hello.str
new file mode 100644
index 00000000..6c121b37
--- /dev/null
+++ b/test/views/hello.str
@@ -0,0 +1 @@
+<h1>Hello From String</h1>
\ No newline at end of file
diff --git a/test/views/layout2.str b/test/views/layout2.str
new file mode 100644
index 00000000..c6391811
--- /dev/null
+++ b/test/views/layout2.str
@@ -0,0 +1,2 @@
+<h1>String Layout!</h1>
+#{yield}
\ No newline at end of file
diff --git a/test/views/nested.str b/test/views/nested.str
new file mode 100644
index 00000000..603038a4
--- /dev/null
+++ b/test/views/nested.str
@@ -0,0 +1 @@
+<content>#{render :str, :hello}</content>
\ No newline at end of file