diff --git a/History.txt b/History.txt
index 1fe095f8..f98912fc 100644
--- a/History.txt
+++ b/History.txt
@@ -2,6 +2,9 @@
   * Major Enhancements
     * Proper plugin system (#19, #100)
     * Add safe mode so unsafe converters/generators can be added
+    * Maruku is now the only processor dependency installed by default.
+      Other processors will be lazy-loaded when necessary (and prompt the
+      user to install them when necessary) (#57)
   * Minor Enhancements
     * Inclusion/exclusion of future dated posts (#59)
     * Generation for a specific time (#59)
diff --git a/bin/jekyll b/bin/jekyll
index b33d4247..fec32d35 100755
--- a/bin/jekyll
+++ b/bin/jekyll
@@ -142,7 +142,11 @@ if options['auto']
   end
 else
   puts "Building site: #{source} -> #{destination}"
-  site.process
+  begin
+    site.process
+  rescue Jekyll::FatalException
+    exit(1)
+  end
   puts "Successfully generated site: #{source} -> #{destination}"
 end
 
diff --git a/jekyll.gemspec b/jekyll.gemspec
index 2cf024f9..71ea1f9d 100644
--- a/jekyll.gemspec
+++ b/jekyll.gemspec
@@ -23,13 +23,16 @@ Gem::Specification.new do |s|
   s.rdoc_options = ["--charset=UTF-8"]
   s.extra_rdoc_files = %w[README.textile LICENSE]
 
-  s.add_runtime_dependency('RedCloth', [">= 4.2.1"])
   s.add_runtime_dependency('liquid', [">= 1.9.0"])
   s.add_runtime_dependency('classifier', [">= 1.3.1"])
-  s.add_runtime_dependency('maruku', [">= 0.5.9"])
   s.add_runtime_dependency('directory_watcher', [">= 1.1.1"])
+  s.add_runtime_dependency('maruku', [">= 0.5.9"])
 
-  s.add_development_dependency('DEVDEPNAME', [">= 1.1.0", "< 2.0.0"])
+  s.add_development_dependency('redgreen', [">= 4.2.1"])
+  s.add_development_dependency('shoulda', [">= 4.2.1"])
+  s.add_development_dependency('rr', [">= 4.2.1"])
+  s.add_development_dependency('cucumber', [">= 4.2.1"])
+  s.add_development_dependency('RedCloth', [">= 4.2.1"])
 
   # = MANIFEST =
   s.files = %w[
diff --git a/lib/jekyll.rb b/lib/jekyll.rb
index ad6cb62a..8229af36 100644
--- a/lib/jekyll.rb
+++ b/lib/jekyll.rb
@@ -22,7 +22,7 @@ require 'yaml'
 
 # 3rd party
 require 'liquid'
-require 'redcloth'
+require 'maruku'
 
 # internal requires
 require 'jekyll/core_ext'
@@ -34,6 +34,7 @@ require 'jekyll/post'
 require 'jekyll/filters'
 require 'jekyll/albino'
 require 'jekyll/static_file'
+require 'jekyll/errors'
 
 # extensions
 require 'jekyll/plugin'
diff --git a/lib/jekyll/converter.rb b/lib/jekyll/converter.rb
index 61398bf1..c2528d14 100644
--- a/lib/jekyll/converter.rb
+++ b/lib/jekyll/converter.rb
@@ -25,6 +25,13 @@ module Jekyll
       @pygments_suffix
     end
 
+    # Initialize the converter.
+    #
+    # Returns an initialized Converter.
+    def initialize(config = {})
+      @config = config
+    end
+
     # Get the pygments prefix.
     #
     # Returns the String prefix.
diff --git a/lib/jekyll/converters/markdown.rb b/lib/jekyll/converters/markdown.rb
index 0210c786..4e50ef5a 100644
--- a/lib/jekyll/converters/markdown.rb
+++ b/lib/jekyll/converters/markdown.rb
@@ -6,36 +6,30 @@ module Jekyll
     pygments_prefix '\n'
     pygments_suffix '\n'
 
-    def initialize(config = {})
+    def setup
+      return if @setup
       # Set the Markdown interpreter (and Maruku self.config, if necessary)
-      case config['markdown']
+      case @config['markdown']
         when 'rdiscount'
           begin
             require 'rdiscount'
-
-            def convert(content)
-              RDiscount.new(content).to_html
-            end
-
           rescue LoadError
-            puts 'You must have the rdiscount gem installed first'
+            STDERR.puts 'You are missing a library required for Markdown. Please run:'
+            STDERR.puts '  $ [sudo] gem install rdiscount'
+            raise FatalException.new("Missing dependency: rdiscount")
           end
         when 'maruku'
           begin
             require 'maruku'
 
-            def convert(content)
-              Maruku.new(content).to_html
-            end
-
-            if config['maruku']['use_divs']
+            if @config['maruku']['use_divs']
               require 'maruku/ext/div'
-              puts 'Maruku: Using extended syntax for div elements.'
+              STDERR.puts 'Maruku: Using extended syntax for div elements.'
             end
 
-            if config['maruku']['use_tex']
+            if @config['maruku']['use_tex']
               require 'maruku/ext/math'
-              puts "Maruku: Using LaTeX extension. Images in `#{config['maruku']['png_dir']}`."
+              STDERR.puts "Maruku: Using LaTeX extension. Images in `#{@config['maruku']['png_dir']}`."
 
               # Switch off MathML output
               MaRuKu::Globals[:html_math_output_mathml] = false
@@ -44,16 +38,21 @@ module Jekyll
               # Turn on math to PNG support with blahtex
               # Resulting PNGs stored in `images/latex`
               MaRuKu::Globals[:html_math_output_png] = true
-              MaRuKu::Globals[:html_png_engine] =  config['maruku']['png_engine']
-              MaRuKu::Globals[:html_png_dir] = config['maruku']['png_dir']
-              MaRuKu::Globals[:html_png_url] = config['maruku']['png_url']
+              MaRuKu::Globals[:html_png_engine] =  @config['maruku']['png_engine']
+              MaRuKu::Globals[:html_png_dir] = @config['maruku']['png_dir']
+              MaRuKu::Globals[:html_png_url] = @config['maruku']['png_url']
             end
           rescue LoadError
-            puts "The maruku gem is required for markdown support!"
+            STDERR.puts 'You are missing a library required for Markdown. Please run:'
+            STDERR.puts '  $ [sudo] gem install maruku'
+            raise FatalException.new("Missing dependency: maruku")
           end
         else
-          raise "Invalid Markdown processor: '#{config['markdown']}' -- did you mean 'maruku' or 'rdiscount'?"
+          STDERR.puts "Invalid Markdown processor: #{@config['markdown']}"
+          STDERR.puts "  Valid options are [ maruku | rdiscount ]"
+          raise FatalException.new("Invalid Markdown process: #{@config['markdown']}")
       end
+      @setup = true
     end
 
     def matches(ext)
@@ -64,6 +63,15 @@ module Jekyll
       ".html"
     end
 
+    def convert(content)
+      setup
+      case @config['markdown']
+        when 'rdiscount'
+          RDiscount.new(content).to_html
+        when 'maruku'
+          Maruku.new(content).to_html
+      end
+    end
   end
 
 end
diff --git a/lib/jekyll/converters/textile.rb b/lib/jekyll/converters/textile.rb
index 60f2153b..072e393a 100644
--- a/lib/jekyll/converters/textile.rb
+++ b/lib/jekyll/converters/textile.rb
@@ -6,6 +6,16 @@ module Jekyll
     pygments_prefix '<notextile>'
     pygments_suffix '</notextile>'
 
+    def setup
+      return if @setup
+      require 'redcloth'
+      @setup = true
+    rescue LoadError
+      STDERR.puts 'You are missing a library required for Textile. Please run:'
+      STDERR.puts '  $ [sudo] gem install RedCloth'
+      raise FatalException.new("Missing dependency: RedCloth")
+    end
+
     def matches(ext)
       ext =~ /textile/i
     end
@@ -15,9 +25,9 @@ module Jekyll
     end
 
     def convert(content)
+      setup
       RedCloth.new(content).to_html
     end
-
   end
 
 end
diff --git a/lib/jekyll/errors.rb b/lib/jekyll/errors.rb
new file mode 100644
index 00000000..296d8371
--- /dev/null
+++ b/lib/jekyll/errors.rb
@@ -0,0 +1,6 @@
+module Jekyll
+
+  class FatalException < StandardError
+  end
+
+end
\ No newline at end of file
diff --git a/test/helper.rb b/test/helper.rb
index 8521bdb4..61636a4e 100644
--- a/test/helper.rb
+++ b/test/helper.rb
@@ -3,6 +3,9 @@ gem 'RedCloth', '>= 4.2.1'
 
 require File.join(File.dirname(__FILE__), *%w[.. lib jekyll])
 
+require 'RedCloth'
+require 'rdiscount'
+
 require 'test/unit'
 require 'redgreen'
 require 'shoulda'
@@ -10,6 +13,9 @@ require 'rr'
 
 include Jekyll
 
+# Send STDERR into the void to suppress program output messages
+STDERR.reopen(test(?e, '/dev/null') ? '/dev/null' : 'NUL:')
+
 class Test::Unit::TestCase
   include RR::Adapters::TestUnit
 
diff --git a/test/test_site.rb b/test/test_site.rb
index 09654ab9..f18791de 100644
--- a/test/test_site.rb
+++ b/test/test_site.rb
@@ -133,18 +133,20 @@ class TestSite < Test::Unit::TestCase
     end
     
     context 'with an invalid markdown processor in the configuration' do
-      
-      should 'give a meaningful error message' do
+      should 'not throw an error at initialization time' do
         bad_processor = 'not a processor name'
-        begin
+        assert_nothing_raised do
           Site.new(Jekyll.configuration.merge({ 'markdown' => bad_processor }))
-          flunk 'Invalid markdown processors should cause a failure on site creation'
-        rescue RuntimeError => e
-          assert e.to_s =~ /invalid|bad/i
-          assert e.to_s =~ %r{#{bad_processor}}
         end
       end
       
+      should 'throw FatalException at process time' do
+        bad_processor = 'not a processor name'
+        s = Site.new(Jekyll.configuration.merge({ 'markdown' => bad_processor }))
+        assert_raise Jekyll::FatalException do
+          s.process
+        end
+      end
     end
     
   end