diff --git a/.pairs b/.pairs
index ec4f2417c..2aafc939d 100644
--- a/.pairs
+++ b/.pairs
@@ -6,7 +6,7 @@ pairs:
   jc: Jerry Cheung; jerry
   bl: Brian Lopez; brian
   jp: Justin Palmer; justin
+  gt: Garen Torikian; garen
 email:
   domain: github.com
 #global: true
-
diff --git a/package.json b/package.json
index 85dec3096..b59587873 100644
--- a/package.json
+++ b/package.json
@@ -19,6 +19,7 @@
     "plist": "git://github.com/nathansobo/node-plist.git",
     "space-pen": "git://github.com/nathansobo/space-pen.git",
     "less": "git://github.com/nathansobo/less.js.git",
+    "roaster": "0.0.3",
     "jqueryui-browser": "1.10.2-1"
   },
 
diff --git a/spec/fixtures/markdown/file.markdown b/spec/fixtures/markdown/file.markdown
index 0eec6a120..964679b09 100644
--- a/spec/fixtures/markdown/file.markdown
+++ b/spec/fixtures/markdown/file.markdown
@@ -1,3 +1,20 @@
 ## File.markdown
 
-:cool:
\ No newline at end of file
+:cool:
+
+```ruby
+def func
+  x = 1
+end
+```
+
+```
+function f(x) {
+  return x++;
+}
+```
+
+```kombucha
+drink-that-stuff:
+  tastes-weird~
+```
diff --git a/src/app/editor.coffee b/src/app/editor.coffee
index 6f81a5d4e..210f10adc 100644
--- a/src/app/editor.coffee
+++ b/src/app/editor.coffee
@@ -43,7 +43,7 @@ class Editor extends View
         @div outlet: 'verticalScrollbarContent'
 
   @classes: ({mini} = {}) ->
-    classes = ['editor']
+    classes = ['editor', 'editor-colors']
     classes.push 'mini' if mini
     classes.join(' ')
 
@@ -1314,18 +1314,44 @@ class Editor extends View
 
   buildLineElementsForScreenRows: (startRow, endRow) ->
     div = document.createElement('div')
-    div.innerHTML = @buildLinesHtml(startRow, endRow)
+    div.innerHTML = @htmlForScreenRows(startRow, endRow)
     new Array(div.children...)
 
-  buildLinesHtml: (startRow, endRow) ->
+  htmlForScreenRows: (startRow, endRow) ->
     lines = @activeEditSession.linesForScreenRows(startRow, endRow)
     htmlLines = []
     screenRow = startRow
     for line in @activeEditSession.linesForScreenRows(startRow, endRow)
-      htmlLines.push(@buildLineHtml(line, screenRow++))
+      htmlLines.push(@htmlForScreenLine(line, screenRow++))
     htmlLines.join('\n\n')
 
-  buildEndOfLineInvisibles: (screenLine) ->
+  htmlForScreenLine: (screenLine, screenRow) ->
+    { tokens, text, lineEnding, fold, isSoftWrapped } =  screenLine
+    if fold
+      attributes = { class: 'fold line', 'fold-id': fold.id }
+    else
+      attributes = { class: 'line' }
+
+    invisibles = @invisibles if @showInvisibles
+    eolInvisibles = @getEndOfLineInvisibles(screenLine)
+    htmlEolInvisibles = @buildHtmlEndOfLineInvisibles(screenLine)
+
+    indentation = Editor.buildIndentation(screenRow, @activeEditSession)
+
+    Editor.buildLineHtml({tokens, text, lineEnding, fold, isSoftWrapped, invisibles, eolInvisibles, htmlEolInvisibles, attributes, @showIndentGuide, indentation, @activeEditSession, @mini})
+
+  @buildIndentation: (screenRow, activeEditSession) ->
+    indentation = 0
+    while --screenRow >= 0
+      bufferRow = activeEditSession.bufferPositionForScreenPosition([screenRow]).row
+      bufferLine = activeEditSession.lineForBufferRow(bufferRow)
+      unless bufferLine is ''
+        indentation = Math.ceil(activeEditSession.indentLevelForLine(bufferLine))
+        break
+
+    indentation
+
+  buildHtmlEndOfLineInvisibles: (screenLine) ->
     invisibles = []
     for invisible in @getEndOfLineInvisibles(screenLine)
       invisibles.push("<span class='invisible-character'>#{invisible}</span>")
@@ -1340,99 +1366,6 @@ class Editor extends View
     invisibles.push(@invisibles.eol) if @invisibles.eol
     invisibles
 
-  buildEmptyLineHtml: (screenLine, screenRow) ->
-    if not @mini and @showIndentGuide
-      indentation = 0
-      while --screenRow >= 0
-        bufferRow = @activeEditSession.bufferPositionForScreenPosition([screenRow]).row
-        bufferLine = @activeEditSession.lineForBufferRow(bufferRow)
-        unless bufferLine is ''
-          indentation = Math.ceil(@activeEditSession.indentLevelForLine(bufferLine))
-          break
-
-      if indentation > 0
-        tabLength = @activeEditSession.getTabLength()
-        invisibles = @getEndOfLineInvisibles(screenLine)
-        indentGuideHtml = []
-        for level in [0...indentation]
-          indentLevelHtml = ["<span class='indent-guide'>"]
-          for characterPosition in [0...tabLength]
-            if invisible = invisibles.shift()
-              indentLevelHtml.push("<span class='invisible-character'>#{invisible}</span>")
-            else
-              indentLevelHtml.push(' ')
-          indentLevelHtml.push("</span>")
-          indentGuideHtml.push(indentLevelHtml.join(''))
-
-        for invisible in invisibles
-          indentGuideHtml.push("<span class='invisible-character'>#{invisible}</span>")
-        return indentGuideHtml.join('')
-
-    invisibles = @buildEndOfLineInvisibles(screenLine)
-    if invisibles.length > 0
-      invisibles
-    else
-      '&nbsp;'
-
-  buildLineHtml: (screenLine, screenRow) ->
-    scopeStack = []
-    line = []
-
-    updateScopeStack = (desiredScopes) ->
-      excessScopes = scopeStack.length - desiredScopes.length
-      _.times(excessScopes, popScope) if excessScopes > 0
-
-      # pop until common prefix
-      for i in [scopeStack.length..0]
-        break if _.isEqual(scopeStack[0...i], desiredScopes[0...i])
-        popScope()
-
-      # push on top of common prefix until scopeStack == desiredScopes
-      for j in [i...desiredScopes.length]
-        pushScope(desiredScopes[j])
-
-    pushScope = (scope) ->
-      scopeStack.push(scope)
-      line.push("<span class=\"#{scope.replace(/\./g, ' ')}\">")
-
-    popScope = ->
-      scopeStack.pop()
-      line.push("</span>")
-
-    if fold = screenLine.fold
-      lineAttributes = { class: 'fold line', 'fold-id': fold.id }
-    else
-      lineAttributes = { class: 'line' }
-
-    attributePairs = []
-    attributePairs.push "#{attributeName}=\"#{value}\"" for attributeName, value of lineAttributes
-    line.push("<div #{attributePairs.join(' ')}>")
-
-    invisibles = @invisibles if @showInvisibles
-
-    if screenLine.text == ''
-      html = @buildEmptyLineHtml(screenLine, screenRow)
-      line.push(html) if html
-    else
-      firstNonWhitespacePosition = screenLine.text.search(/\S/)
-      firstTrailingWhitespacePosition = screenLine.text.search(/\s*$/)
-      lineIsWhitespaceOnly = firstTrailingWhitespacePosition is 0
-      position = 0
-      for token in screenLine.tokens
-        updateScopeStack(token.scopes)
-        hasLeadingWhitespace =  position < firstNonWhitespacePosition
-        hasTrailingWhitespace = position + token.value.length > firstTrailingWhitespacePosition
-        hasIndentGuide = not @mini and @showIndentGuide and (hasLeadingWhitespace or lineIsWhitespaceOnly)
-        line.push(token.getValueAsHtml({invisibles, hasLeadingWhitespace, hasTrailingWhitespace, hasIndentGuide}))
-        position += token.value.length
-
-    popScope() while scopeStack.length > 0
-    line.push(@buildEndOfLineInvisibles(screenLine)) unless screenLine.text == ''
-    line.push("<span class='fold-marker'/>") if fold
-
-    line.push('</div>')
-    line.join('')
-
   lineElementForScreenRow: (screenRow) ->
     @renderedLines.children(":eq(#{screenRow - @firstRenderedScreenRow})")
 
@@ -1457,7 +1390,7 @@ class Editor extends View
   #
   # Returns an object with two values: `top` and `left`, representing the pixel positions.
   pixelPositionForScreenPosition: (position) ->
-    return { top: 0, left: 0 } unless @isOnDom() and @isVisible()
+    return { top: 0, left: 0 } unless @isOnDom() and @isVisible()
     {row, column} = Point.fromObject(position)
     actualRow = Math.floor(row)
 
@@ -1552,6 +1485,84 @@ class Editor extends View
 
   ### Internal ###
 
+  @buildLineHtml: ({tokens, text, lineEnding, fold, isSoftWrapped, invisibles, eolInvisibles, htmlEolInvisibles, attributes, showIndentGuide, indentation, activeEditSession, mini}) ->
+    scopeStack = []
+    line = []
+
+    updateScopeStack = (desiredScopes) ->
+      excessScopes = scopeStack.length - desiredScopes.length
+      _.times(excessScopes, popScope) if excessScopes > 0
+
+      # pop until common prefix
+      for i in [scopeStack.length..0]
+        break if _.isEqual(scopeStack[0...i], desiredScopes[0...i])
+        popScope()
+
+      # push on top of common prefix until scopeStack == desiredScopes
+      for j in [i...desiredScopes.length]
+        pushScope(desiredScopes[j])
+
+    pushScope = (scope) ->
+      scopeStack.push(scope)
+      line.push("<span class=\"#{scope.replace(/\./g, ' ')}\">")
+
+    popScope = ->
+      scopeStack.pop()
+      line.push("</span>")
+
+    attributePairs = []
+    attributePairs.push "#{attributeName}=\"#{value}\"" for attributeName, value of attributes
+    line.push("<div #{attributePairs.join(' ')}>")
+
+    if text == ''
+      html = Editor.buildEmptyLineHtml(showIndentGuide, eolInvisibles, htmlEolInvisibles, indentation, activeEditSession, mini)
+      line.push(html) if html
+    else
+      firstNonWhitespacePosition = text.search(/\S/)
+      firstTrailingWhitespacePosition = text.search(/\s*$/)
+      lineIsWhitespaceOnly = firstTrailingWhitespacePosition is 0
+      position = 0
+      for token in tokens
+        updateScopeStack(token.scopes)
+        hasLeadingWhitespace =  position < firstNonWhitespacePosition
+        hasTrailingWhitespace = position + token.value.length > firstTrailingWhitespacePosition
+        hasIndentGuide = not mini and showIndentGuide and (hasLeadingWhitespace or lineIsWhitespaceOnly)
+        line.push(token.getValueAsHtml({invisibles, hasLeadingWhitespace, hasTrailingWhitespace, hasIndentGuide}))
+        position += token.value.length
+
+    popScope() while scopeStack.length > 0
+    line.push(htmlEolInvisibles) unless text == ''
+    line.push("<span class='fold-marker'/>") if fold
+
+    line.push('</div>')
+    line.join('')
+
+  @buildEmptyLineHtml: (showIndentGuide, eolInvisibles, htmlEolInvisibles, indentation, activeEditSession, mini) ->
+    if not mini and showIndentGuide
+      if indentation > 0
+        tabLength = activeEditSession.getTabLength()
+        indentGuideHtml = []
+        for level in [0...indentation]
+          indentLevelHtml = ["<span class='indent-guide'>"]
+          for characterPosition in [0...tabLength]
+            if invisible = eolInvisibles.shift()
+              indentLevelHtml.push("<span class='invisible-character'>#{invisible}</span>")
+            else
+              indentLevelHtml.push(' ')
+          indentLevelHtml.push("</span>")
+          indentGuideHtml.push(indentLevelHtml.join(''))
+
+        for invisible in eolInvisibles
+          indentGuideHtml.push("<span class='invisible-character'>#{invisible}</span>")
+
+        return indentGuideHtml.join('')
+
+    invisibles = htmlEolInvisibles
+    if invisibles.length > 0
+      invisibles
+    else
+      '&nbsp;'
+
   bindToKeyedEvent: (key, event, callback) ->
     binding = {}
     binding[key] = event
diff --git a/src/packages/markdown-preview/lib/markdown-preview-view.coffee b/src/packages/markdown-preview/lib/markdown-preview-view.coffee
index 9b336cc2e..6f0c231e1 100644
--- a/src/packages/markdown-preview/lib/markdown-preview-view.coffee
+++ b/src/packages/markdown-preview/lib/markdown-preview-view.coffee
@@ -1,6 +1,17 @@
 $ = require 'jquery'
+_ = require 'underscore'
 ScrollView = require 'scroll-view'
 {$$$} = require 'space-pen'
+roaster = require 'roaster'
+Editor = require 'editor'
+
+fenceNameToExtension =
+  "coffeescript": "coffee"
+  "toml": "toml"
+  "ruby": "rb"
+  "go": "go"
+  "mustache": "mustache"
+  "java": "java"
 
 module.exports =
 class MarkdownPreviewView extends ScrollView
@@ -15,13 +26,13 @@ class MarkdownPreviewView extends ScrollView
   initialize: (@buffer) ->
     super
 
-    @fetchRenderedMarkdown()
+    @renderMarkdown()
     @on 'core:move-up', => @scrollUp()
     @on 'core:move-down', => @scrollDown()
 
   afterAttach: (onDom) ->
     @subscribe @buffer, 'saved', =>
-      @fetchRenderedMarkdown()
+      @renderMarkdown()
       pane = @getPane()
       pane.showItem(this) if pane? and pane isnt rootView.getActivePane()
 
@@ -42,7 +53,7 @@ class MarkdownPreviewView extends ScrollView
     @buffer.getPath()
 
   setErrorHtml: (result)->
-    try failureMessage = JSON.parse(result.responseText).message
+    try failureMessage = JSON.parse(result).message
 
     @html $$$ ->
       @h2 'Previewing Markdown Failed'
@@ -59,15 +70,38 @@ class MarkdownPreviewView extends ScrollView
   setLoading: ->
     @html($$$ -> @div class: 'markdown-spinner', 'Loading Markdown...')
 
-  fetchRenderedMarkdown: (text) ->
+
+  tokenizeCodeBlocks: (html) =>
+    html = $(html)
+    preList = $(html.filter("pre"))
+
+    for preElement in preList.toArray()
+      $(preElement).addClass("editor-colors")
+      codeBlock = $(preElement.firstChild)
+
+      # go to next block unless this one has a class
+      continue unless className = codeBlock.attr('class')
+
+      fenceName = className.replace(/^lang-/, '')
+      # go to next block unless the class name is matches `lang`
+      continue unless extension = fenceNameToExtension[fenceName]
+      text = codeBlock.text()
+
+      # go to next block if this grammar is not mapped
+      continue unless grammar = syntax.selectGrammar("foo.#{extension}", text)
+      continue if grammar is syntax.nullGrammar
+
+      codeBlock.empty()
+      for tokens in grammar.tokenizeLines(text)
+        codeBlock.append(Editor.buildLineHtml({ tokens, text }))
+
+    html
+
+  renderMarkdown: ->
     @setLoading()
-    $.ajax
-      url: 'https://api.github.com/markdown'
-      type: 'POST'
-      dataType: 'html'
-      contentType: 'application/json; charset=UTF-8'
-      data: JSON.stringify
-        mode: 'markdown'
-        text: @buffer.getText()
-      success: (html) => @html(html)
-      error: (result) => @setErrorHtml(result)
+    roaster(@buffer.getText(), {}, (err, html) =>
+      if err
+        @setErrorHtml(err)
+      else
+        @html(@tokenizeCodeBlocks(html))
+    )
diff --git a/src/packages/markdown-preview/lib/markdown-preview.coffee b/src/packages/markdown-preview/lib/markdown-preview.coffee
index 8011339b9..90bb96f86 100644
--- a/src/packages/markdown-preview/lib/markdown-preview.coffee
+++ b/src/packages/markdown-preview/lib/markdown-preview.coffee
@@ -18,7 +18,7 @@ module.exports =
     {previewPane, previewItem} = @getExistingPreview(editSession)
     if previewItem?
       previewPane.showItem(previewItem)
-      previewItem.fetchRenderedMarkdown()
+      previewItem.renderMarkdown()
     else if nextPane = activePane.getNextPane()
       nextPane.showItem(new MarkdownPreviewView(editSession.buffer))
     else
diff --git a/src/packages/markdown-preview/spec/markdown-preview-spec.coffee b/src/packages/markdown-preview/spec/markdown-preview-spec.coffee
index 8e590a229..5c816d4fe 100644
--- a/src/packages/markdown-preview/spec/markdown-preview-spec.coffee
+++ b/src/packages/markdown-preview/spec/markdown-preview-spec.coffee
@@ -8,7 +8,7 @@ describe "MarkdownPreview package", ->
     project.setPath(project.resolve('markdown'))
     window.rootView = new RootView
     atom.activatePackage("markdown-preview", immediate: true)
-    spyOn(MarkdownPreviewView.prototype, 'fetchRenderedMarkdown')
+    spyOn(MarkdownPreviewView.prototype, 'renderMarkdown')
 
   describe "markdown-preview:show", ->
     beforeEach ->
@@ -61,9 +61,9 @@ describe "MarkdownPreview package", ->
             [pane] = rootView.getPanes()
             pane.focus()
 
-            MarkdownPreviewView.prototype.fetchRenderedMarkdown.reset()
+            MarkdownPreviewView.prototype.renderMarkdown.reset()
             pane.activeItem.buffer.trigger 'saved'
-            expect(MarkdownPreviewView.prototype.fetchRenderedMarkdown).not.toHaveBeenCalled()
+            expect(MarkdownPreviewView.prototype.renderMarkdown).not.toHaveBeenCalled()
 
       describe "when a preview item has already been created for the edit session's uri", ->
         it "updates and shows the existing preview item if it isn't displayed", ->
@@ -77,9 +77,9 @@ describe "MarkdownPreview package", ->
           expect(pane2.activeItem).not.toBe preview
           pane1.focus()
 
-          preview.fetchRenderedMarkdown.reset()
+          preview.renderMarkdown.reset()
           rootView.getActiveView().trigger 'markdown-preview:show'
-          expect(preview.fetchRenderedMarkdown).toHaveBeenCalled()
+          expect(preview.renderMarkdown).toHaveBeenCalled()
           expect(rootView.getPanes()).toHaveLength 2
           expect(pane2.getItems()).toHaveLength 2
           expect(pane2.activeItem).toBe preview
@@ -95,9 +95,9 @@ describe "MarkdownPreview package", ->
               pane1.showItemAtIndex(0)
               preview = pane1.itemAtIndex(1)
 
-              preview.fetchRenderedMarkdown.reset()
+              preview.renderMarkdown.reset()
               pane1.activeItem.buffer.trigger 'saved'
-              expect(preview.fetchRenderedMarkdown).toHaveBeenCalled()
+              expect(preview.renderMarkdown).toHaveBeenCalled()
               expect(pane1.activeItem).not.toBe preview
 
           describe "when the preview is not in the same pane", ->
@@ -109,7 +109,7 @@ describe "MarkdownPreview package", ->
               expect(pane2.activeItem).not.toBe preview
               pane1.focus()
 
-              preview.fetchRenderedMarkdown.reset()
+              preview.renderMarkdown.reset()
               pane1.activeItem.buffer.trigger 'saved'
-              expect(preview.fetchRenderedMarkdown).toHaveBeenCalled()
+              expect(preview.renderMarkdown).toHaveBeenCalled()
               expect(pane2.activeItem).toBe preview
diff --git a/src/packages/markdown-preview/spec/markdown-preview-view-spec.coffee b/src/packages/markdown-preview/spec/markdown-preview-view-spec.coffee
index 42cac9b84..b3ae8b63c 100644
--- a/src/packages/markdown-preview/spec/markdown-preview-view-spec.coffee
+++ b/src/packages/markdown-preview/spec/markdown-preview-view-spec.coffee
@@ -6,34 +6,39 @@ describe "MarkdownPreviewView", ->
   [buffer, preview] = []
 
   beforeEach ->
-    spyOn($, 'ajax')
     project.setPath(project.resolve('markdown'))
     buffer = project.bufferForPath('file.markdown')
+    atom.activatePackage('ruby.tmbundle', sync: true)
     preview = new MarkdownPreviewView(buffer)
 
   afterEach ->
     buffer.release()
 
   describe "on construction", ->
-    ajaxArgs = null
 
-    beforeEach ->
-      ajaxArgs = $.ajax.argsForCall[0][0]
-
-    it "shows a loading spinner and fetches the rendered markdown", ->
+    it "shows a loading spinner and renders the markdown", ->
+      preview.setLoading()
       expect(preview.find('.markdown-spinner')).toExist()
-      expect($.ajax).toHaveBeenCalled()
+      expect(preview.buffer.getText()).toBe buffer.getText()
 
-      expect(JSON.parse(ajaxArgs.data).text).toBe buffer.getText()
-
-      ajaxArgs.success($$$ -> @div "WWII", class: 'private-ryan')
-      expect(preview.find(".private-ryan")).toExist()
+      preview.renderMarkdown()
+      expect(preview.find(".emoji")).toExist()
 
     it "shows an error message on error", ->
-      ajaxArgs.error()
+      preview.setErrorHtml("Not a real file")
       expect(preview.text()).toContain "Failed"
 
   describe "serialization", ->
     it "reassociates with the same buffer when deserialized", ->
       newPreview = deserialize(preview.serialize())
       expect(newPreview.buffer).toBe buffer
+
+  describe "code block tokenization", ->
+    describe "when the code block's fence name has a matching grammar", ->
+      it "tokenizes the code block with the grammar", ->
+        expect(preview.find("pre span.entity.name.function.ruby")).toExist()
+
+    describe "when the code block's fence name doesn't have a matching grammar", ->
+      it "does not tokenize the code block", ->
+        expect(preview.find("pre code:not([class])").children().length).toBe 0
+        expect(preview.find("pre code.lang-kombucha").children().length).toBe 0
diff --git a/src/packages/markdown-preview/stylesheets/markdown-preview.less b/src/packages/markdown-preview/stylesheets/markdown-preview.less
index 608389a88..4265e8cac 100644
--- a/src/packages/markdown-preview/stylesheets/markdown-preview.less
+++ b/src/packages/markdown-preview/stylesheets/markdown-preview.less
@@ -23,6 +23,7 @@
 // includes some GitHub Flavored Markdown specific styling (like @mentions)
 .markdown-preview {
   pre,
+  pre div.editor,
   code,
   tt {
     font-size: 12px;
@@ -385,7 +386,6 @@
   }
 
   .highlight pre, pre {
-    background-color: #f8f8f8;
     border: 1px solid #ccc;
     font-size: 13px;
     line-height: 19px;
@@ -400,4 +400,9 @@
     background-color: transparent;
     border: none;
   }
+
+  .emoji {
+    height: 20px;
+    width: 20px;
+  }
 }
diff --git a/themes/atom-dark-syntax.css b/themes/atom-dark-syntax.css
index a095d3018..357f0886e 100644
--- a/themes/atom-dark-syntax.css
+++ b/themes/atom-dark-syntax.css
@@ -1,4 +1,4 @@
-.editor, .editor .gutter {
+.editor-colors {
   background-color: #1d1f21;
   color: #c5c8c6;
 }