diff --git a/src/main/scala/app/IssuesController.scala b/src/main/scala/app/IssuesController.scala
index e430bb2..307610d 100644
--- a/src/main/scala/app/IssuesController.scala
+++ b/src/main/scala/app/IssuesController.scala
@@ -158,7 +158,7 @@
           org.json4s.jackson.Serialization.write(
               Map("title"   -> x.title,
                   "content" -> view.Markdown.toHtml(x.content getOrElse "No description given.",
-                      repository, false, true, true)
+                      repository, false, true)
               ))
         }
       } else Unauthorized
@@ -175,7 +175,7 @@
           contentType = formats("json")
           org.json4s.jackson.Serialization.write(
               Map("content" -> view.Markdown.toHtml(x.content,
-                  repository, false, true, true)
+                  repository, false, true)
               ))
         }
       } else Unauthorized
diff --git a/src/main/scala/app/RepositoryViewerController.scala b/src/main/scala/app/RepositoryViewerController.scala
index a70c254..43cb126 100644
--- a/src/main/scala/app/RepositoryViewerController.scala
+++ b/src/main/scala/app/RepositoryViewerController.scala
@@ -27,8 +27,7 @@
     contentType = "text/html"
     view.helpers.markdown(params("content"), repository,
       params("enableWikiLink").toBoolean,
-      params("enableCommitLink").toBoolean,
-      params("enableIssueLink").toBoolean)
+      params("enableRefsLink").toBoolean)
   })
 
   /**
diff --git a/src/main/scala/service/RequestCache.scala b/src/main/scala/service/RequestCache.scala
new file mode 100644
index 0000000..758c373
--- /dev/null
+++ b/src/main/scala/service/RequestCache.scala
@@ -0,0 +1,26 @@
+package service
+
+import model._
+
+/**
+ * This service is used for a view helper mainly.
+ *
+ * It may be called many times in one request, so each method stores
+ * its result into the cache which available during a request.
+ */
+trait RequestCache {
+
+  def getIssue(userName: String, repositoryName: String, issueId: String)(implicit context: app.Context): Option[Issue] = {
+    context.cache(s"issue.${userName}/${repositoryName}#${issueId}"){
+      new IssuesService {}.getIssue(userName, repositoryName, issueId)
+    }
+  }
+
+  def getAccountByUserName(userName: String)(implicit context: app.Context): Option[Account] = {
+    context.cache(s"account.${userName}"){
+      new AccountService {}.getAccountByUserName(userName)
+    }
+  }
+
+}
+
diff --git a/src/main/scala/util/Implicits.scala b/src/main/scala/util/Implicits.scala
index 1de9e24..c475136 100644
--- a/src/main/scala/util/Implicits.scala
+++ b/src/main/scala/util/Implicits.scala
@@ -1,7 +1,7 @@
 package util
 
-import twirl.api.Html
 import scala.slick.driver.H2Driver.simple._
+import scala.util.matching.Regex
 
 /**
  * Provides some usable implicit conversions.
@@ -30,4 +30,23 @@
     def &&(c2: => Column[Boolean], guard: => Boolean): Column[Boolean] = if(guard) c1 && c2 else c1
   }
 
+  implicit class RichString(value: String){
+    def replaceBy(regex: Regex)(replace: Regex.MatchData => Option[String]): String = {
+      val sb = new StringBuilder()
+      var i = 0
+      regex.findAllIn(value).matchData.foreach { m =>
+        sb.append(value.substring(i, m.start))
+        i = m.end
+        replace(m) match {
+          case Some(s) => sb.append(s)
+          case None    => sb.append(m.matched)
+        }
+      }
+      if(i < value.length){
+        sb.append(value.substring(i))
+      }
+      sb.toString
+    }
+  }
+
 }
\ No newline at end of file
diff --git a/src/main/scala/view/AvatarImageProvider.scala b/src/main/scala/view/AvatarImageProvider.scala
new file mode 100644
index 0000000..33ac699
--- /dev/null
+++ b/src/main/scala/view/AvatarImageProvider.scala
@@ -0,0 +1,26 @@
+package view
+
+import service.RequestCache
+import twirl.api.Html
+import util.StringUtil
+
+trait AvatarImageProvider { self: RequestCache =>
+
+  /**
+   * Returns &lt;img&gt; which displays the avatar icon.
+   * Looks up Gravatar if avatar icon has not been configured in user settings.
+   */
+  protected def getAvatarImageHtml(userName: String, size: Int, tooltip: Boolean = false)(implicit context: app.Context): Html = {
+    val src = getAccountByUserName(userName).collect { case account if(account.image.isEmpty) =>
+      s"""http://www.gravatar.com/avatar/${StringUtil.md5(account.mailAddress)}?s=${size}"""
+    } getOrElse {
+      s"""${context.path}/${userName}/_avatar"""
+    }
+    if(tooltip){
+      Html(s"""<img src=${src} class="avatar" style="width: ${size}px; height: ${size}px;" data-toggle="tooltip" title=${userName}/>""")
+    } else {
+      Html(s"""<img src=${src} class="avatar" style="width: ${size}px; height: ${size}px;" />""")
+    }
+  }
+
+}
\ No newline at end of file
diff --git a/src/main/scala/view/LinkConverter.scala b/src/main/scala/view/LinkConverter.scala
new file mode 100644
index 0000000..968f34f
--- /dev/null
+++ b/src/main/scala/view/LinkConverter.scala
@@ -0,0 +1,33 @@
+package view
+
+import service.RequestCache
+import util.Implicits.RichString
+
+trait LinkConverter { self: RequestCache =>
+
+  /**
+   * Converts issue id, username and commit id to link.
+   */
+  protected def convertRefsLinks(value: String, repository: service.RepositoryService.RepositoryInfo,
+                                 issueIdPrefix: String =  "#")(implicit context: app.Context): String = {
+    value
+      // escape HTML tags
+      .replaceAll("&", "&amp;").replaceAll("<", "&lt;").replaceAll(">", "&gt;").replaceAll("\"", "&quot;")
+      // convert issue id to link
+      .replaceBy(("(^|\\W)" + issueIdPrefix + "(\\d+)(\\W|$)").r){ m =>
+        if(getIssue(repository.owner, repository.name, m.group(2)).isDefined){
+          Some(s"""${m.group(1)}<a href="${context.path}/${repository.owner}/${repository.name}/issues/${m.group(2)}">#${m.group(2)}</a>${m.group(3)}""")
+        } else {
+          Some(s"""${m.group(1)}#${m.group(2)}${m.group(3)}""")
+        }
+      }
+      // convert @username to link
+      .replaceBy("(^|\\W)@([a-zA-Z0-9\\-_]+)(\\W|$)".r){ m =>
+        getAccountByUserName(m.group(2)).map { _ =>
+          s"""${m.group(1)}<a href="${context.path}/${m.group(2)}">@${m.group(2)}</a>${m.group(3)}"""
+        }
+      }
+      // convert commit id to link
+      .replaceAll("(^|\\W)([a-f0-9]{40})(\\W|$)", s"""$$1<a href="${context.path}/${repository.owner}/${repository.name}/commit/$$2">$$2</a>$$3""")
+  }
+}
diff --git a/src/main/scala/view/Markdown.scala b/src/main/scala/view/Markdown.scala
index b90ba10..51f3375 100644
--- a/src/main/scala/view/Markdown.scala
+++ b/src/main/scala/view/Markdown.scala
@@ -1,11 +1,13 @@
 package view
 
 import util.StringUtil
+import util.Implicits._
 import org.parboiled.common.StringUtils
 import org.pegdown._
 import org.pegdown.ast._
 import org.pegdown.LinkRenderer.Rendering
 import scala.collection.JavaConverters._
+import service.RequestCache
 
 object Markdown {
 
@@ -13,12 +15,17 @@
    * Converts Markdown of Wiki pages to HTML.
    */
   def toHtml(markdown: String, repository: service.RepositoryService.RepositoryInfo,
-             enableWikiLink: Boolean, enableCommitLink: Boolean, enableIssueLink: Boolean)(implicit context: app.Context): String = {
+             enableWikiLink: Boolean, enableRefsLink: Boolean)(implicit context: app.Context): String = {
+    // escape issue id
+    val source = if(enableRefsLink){
+      markdown.replaceAll("(^|\\W)#([0-9]+)(\\W|$)", "$1issue:$2$3")
+    } else markdown
+
     val rootNode = new PegDownProcessor(
       Extensions.AUTOLINKS | Extensions.WIKILINKS | Extensions.FENCED_CODE_BLOCKS | Extensions.TABLES
-    ).parseMarkdown(markdown.toCharArray)
+    ).parseMarkdown(source.toCharArray)
 
-    new GitBucketHtmlSerializer(markdown, context, repository, enableWikiLink, enableCommitLink, enableIssueLink).toHtml(rootNode)
+    new GitBucketHtmlSerializer(markdown, repository, enableWikiLink, enableRefsLink).toHtml(rootNode)
   }
 }
 
@@ -64,15 +71,13 @@
 
 class GitBucketHtmlSerializer(
     markdown: String,
-    context: app.Context,
     repository: service.RepositoryService.RepositoryInfo,
     enableWikiLink: Boolean,
-    enableCommitLink: Boolean,
-    enableIssueLink: Boolean
-  ) extends ToHtmlSerializer(
+    enableRefsLink: Boolean
+  )(implicit val context: app.Context) extends ToHtmlSerializer(
     new GitBucketLinkRender(context, repository, enableWikiLink),
     Map[String, VerbatimSerializer](VerbatimSerializer.DEFAULT -> new GitBucketVerbatimSerializer).asJava
-  ) {
+  ) with LinkConverter with RequestCache {
 
   override protected def printImageTag(imageNode: SuperNode, url: String): Unit =
     printer.print("<img src=\"").print(fixUrl(url)).print("\"  alt=\"").printEncoded(printChildrenToString(imageNode)).print("\"/>")
@@ -100,10 +105,7 @@
 
   override def visit(node: TextNode) {
     // convert commit id and username to link.
-    val text = if(enableCommitLink) node.getText
-      .replaceAll("(^|\\W)([0-9a-f]{40})(\\W|$)", s"""$$1<a href="${context.path}/${repository.owner}/${repository.name}/commit/$$2">$$2</a>$$3""")
-      .replaceAll("(^|\\W)@([a-zA-Z0-9\\-_]+)(\\W|$)", s"""$$1<a href="${context.path}/$$2">@$$2</a>$$3""")
-    else node.getText
+    val text = if(enableRefsLink) convertRefsLinks(node.getText, repository, "issue:") else node.getText
 
     if (abbreviations.isEmpty) {
       printer.print(text)
@@ -112,15 +114,4 @@
     }
   }
 
-  override def visit(node: HeaderNode) {
-    val text = markdown.substring(node.getStartIndex, node.getEndIndex - 1).trim
-    if(enableIssueLink && text.matches("#[\\d]+")){
-      // convert issue id to link
-      val issueId = text.substring(1).toInt
-      printer.print(s"""<a href="${context.path}/${repository.owner}/${repository.name}/issues/${issueId}">#${issueId}</a>""")
-    } else {
-      printTag(node, "h" + node.getLevel)
-    }
-  }
-
 }
\ No newline at end of file
diff --git a/src/main/scala/view/helpers.scala b/src/main/scala/view/helpers.scala
index 74d06bf..fa276a2 100644
--- a/src/main/scala/view/helpers.scala
+++ b/src/main/scala/view/helpers.scala
@@ -3,12 +3,12 @@
 import java.text.SimpleDateFormat
 import twirl.api.Html
 import util.StringUtil
-import service.AccountService
+import service.RequestCache
 
 /**
  * Provides helper methods for Twirl templates.
  */
-object helpers {
+object helpers extends AvatarImageProvider with LinkConverter with RequestCache {
   
   /**
    * Format java.util.Date to "yyyy-MM-dd HH:mm:ss".
@@ -31,10 +31,23 @@
    * Converts Markdown of Wiki pages to HTML.
    */
   def markdown(value: String, repository: service.RepositoryService.RepositoryInfo,
-               enableWikiLink: Boolean, enableCommitLink: Boolean, enableIssueLink: Boolean)(implicit context: app.Context): Html = {
-    Html(Markdown.toHtml(value, repository, enableWikiLink, enableCommitLink, enableIssueLink))
+               enableWikiLink: Boolean, enableRefsLink: Boolean)(implicit context: app.Context): Html = {
+    Html(Markdown.toHtml(value, repository, enableWikiLink, enableRefsLink))
   }
 
+  /**
+   * Returns &lt;img&gt; which displays the avatar icon.
+   * Looks up Gravatar if avatar icon has not been configured in user settings.
+   */
+  def avatar(userName: String, size: Int, tooltip: Boolean = false)(implicit context: app.Context): Html =
+    getAvatarImageHtml(userName, size, tooltip)
+
+  /**
+   * Converts commit id, issue id and username to the link.
+   */
+  def link(value: String, repository: service.RepositoryService.RepositoryInfo)(implicit context: app.Context): Html =
+    Html(convertRefsLinks(value, repository))
+
   def activityMessage(message: String)(implicit context: app.Context): Html =
     Html(message
       .replaceAll("\\[issue:([^\\s]+?)/([^\\s]+?)#((\\d+))\\]"   , s"""<a href="${context.path}/$$1/$$2/issues/$$3">$$1/$$2#$$3</a>""")
@@ -66,38 +79,6 @@
   def assets(implicit context: app.Context): String =
     s"${context.path}/assets"
 
-  /**
-   * Converts issue id and commit id to link.
-   */
-  def link(value: String, repository: service.RepositoryService.RepositoryInfo)(implicit context: app.Context): Html =
-    Html(value
-      // escape HTML tags
-      .replaceAll("&", "&amp;").replaceAll("<", "&lt;").replaceAll(">", "&gt;").replaceAll("\"", "&quot;")
-      // convert issue id to link
-      .replaceAll("(^|\\W)#(\\d+)(\\W|$)", s"""$$1<a href="${context.path}/${repository.owner}/${repository.name}/issues/$$2">#$$2</a>$$3""")
-      // convert commit id to link
-      .replaceAll("(^|\\W)([a-f0-9]{40})(\\W|$)", s"""$$1<a href="${context.path}/${repository.owner}/${repository.name}/commit/$$2">$$2</a>$$3"""))
-
-
-  /**
-   * Returns &lt;img&gt; which displays the avatar icon.
-   * Looks up Gravatar if avatar icon has not been configured in user settings.
-   */
-  def avatar(userName: String, size: Int, tooltip: Boolean = false)(implicit context: app.Context): Html = {
-    val account = context.cache(s"account.${userName}"){
-      new AccountService {}.getAccountByUserName(userName)
-    }
-    val src = account.collect { case account if(account.image.isEmpty) =>
-      s"""http://www.gravatar.com/avatar/${StringUtil.md5(account.mailAddress)}?s=${size}"""
-    } getOrElse {
-      s"""${context.path}/${userName}/_avatar"""
-    }
-    if(tooltip){
-      Html(s"""<img src=${src} class="avatar" style="width: ${size}px; height: ${size}px;" data-toggle="tooltip" title=${userName}/>""")
-    } else {
-      Html(s"""<img src=${src} class="avatar" style="width: ${size}px; height: ${size}px;" />""")
-    }
-  }
 
   /**
    * Implicit conversion to add mkHtml() to Seq[Html].
diff --git a/src/main/twirl/helper/preview.scala.html b/src/main/twirl/helper/preview.scala.html
index 642c3bc..9c1a607 100644
--- a/src/main/twirl/helper/preview.scala.html
+++ b/src/main/twirl/helper/preview.scala.html
@@ -1,5 +1,5 @@
-@(repository: service.RepositoryService.RepositoryInfo, content: String, enableWikiLink: Boolean,
-  enableCommitLink: Boolean, enableIssueLink: Boolean, style: String = "", placeholder: String = "Leave a comment")(implicit context: app.Context)
+@(repository: service.RepositoryService.RepositoryInfo, content: String, enableWikiLink: Boolean, enableRefsLink: Boolean,
+  style: String = "", placeholder: String = "Leave a comment")(implicit context: app.Context)
 @import context._
 @import view.helpers._
 <div class="tabbable">
@@ -30,10 +30,9 @@
   $('#preview').click(function(){
     $('#preview-area').html('<img src="@assets/common/images/indicator.gif"> Previewing...');
     $.post('@url(repository)/_preview', {
-      content          : $('#content').val(),
-      enableWikiLink   : @enableWikiLink,
-      enableCommitLink : @enableCommitLink,
-      enableIssueLink  : @enableIssueLink
+      content        : $('#content').val(),
+      enableWikiLink : @enableWikiLink,
+      enableRefsLink : @enableRefsLink
     }, function(data){
       $('#preview-area').html(data);
       prettyPrint();
diff --git a/src/main/twirl/issues/create.scala.html b/src/main/twirl/issues/create.scala.html
index 68d8eff..fec4193 100644
--- a/src/main/twirl/issues/create.scala.html
+++ b/src/main/twirl/issues/create.scala.html
@@ -43,7 +43,7 @@
             </div>
           </div>
           <hr>
-          @helper.html.preview(repository, "", false, true, true, "width: 600px; height: 200px;")
+          @helper.html.preview(repository, "", false, true, "width: 600px; height: 200px;")
         </div>
       </div>
       <div class="pull-right">
diff --git a/src/main/twirl/issues/issue.scala.html b/src/main/twirl/issues/issue.scala.html
index c36405b..a12eafe 100644
--- a/src/main/twirl/issues/issue.scala.html
+++ b/src/main/twirl/issues/issue.scala.html
@@ -64,7 +64,7 @@
             </div>
           </div>
           <div class="issue-content" id="issueContent">
-            @markdown(issue.content getOrElse "No description given.", repository, false, true, true)
+            @markdown(issue.content getOrElse "No description given.", repository, false, true)
           </div>
         </div>
       </div>
@@ -82,7 +82,7 @@
             </span>
           </div>
           <div class="box-content"class="issue-content" id="commentContent-@comment.commentId">
-            @markdown(comment.content, repository, false, true, true)
+            @markdown(comment.content, repository, false, true)
           </div>
         </div>
         @comment.action.map { action =>
@@ -102,7 +102,7 @@
           <div class="issue-avatar-image">@avatar(loginAccount.get.userName, 48)</div>
           <div class="box issue-comment-box">
             <div class="box-content">
-              @helper.html.preview(repository, "", false, true, true, "width: 680px; height: 100px;")
+              @helper.html.preview(repository, "", false, true, "width: 680px; height: 100px;")
             </div>
           </div>
           <div class="pull-right">
diff --git a/src/main/twirl/issues/milestones/list.scala.html b/src/main/twirl/issues/milestones/list.scala.html
index 76b5c24..e9ddb6c 100644
--- a/src/main/twirl/issues/milestones/list.scala.html
+++ b/src/main/twirl/issues/milestones/list.scala.html
@@ -81,7 +81,7 @@
               </div>
               @if(milestone.description.isDefined){
                 <div class="milestone-description">
-                  @markdown(milestone.description.get, repository, false, false, false)
+                  @markdown(milestone.description.get, repository, false, false)
                 </div>
               }
             </td>
diff --git a/src/main/twirl/repo/files.scala.html b/src/main/twirl/repo/files.scala.html
index 1cb2434..541ccdf 100644
--- a/src/main/twirl/repo/files.scala.html
+++ b/src/main/twirl/repo/files.scala.html
@@ -27,8 +27,6 @@
           <a href="@url(repository)/commit/@latestCommit.id" class="commit-message">@link(latestCommit.summary, repository)</a>
           @if(latestCommit.description.isDefined){
             <a href="javascript:void(0)" onclick="$('#description-@latestCommit.id').toggle();" class="omit">...</a>
-          }
-          @if(latestCommit.description.isDefined){
             <pre id="description-@latestCommit.id" class="commit-description" style="display: none;">@link(latestCommit.description.get, repository)</pre>
           }
         </th>
@@ -79,7 +77,7 @@
   @readme.map { content =>
   <div class="box">
     <div class="box-header">README.md</div>
-    <div class="box-content">@markdown(content, repository, false, false, false)</div>
+    <div class="box-content">@markdown(content, repository, false, false)</div>
   </div>
   }
 }
\ No newline at end of file
diff --git a/src/main/twirl/wiki/edit.scala.html b/src/main/twirl/wiki/edit.scala.html
index 3da2b6c..580c83b 100644
--- a/src/main/twirl/wiki/edit.scala.html
+++ b/src/main/twirl/wiki/edit.scala.html
@@ -23,7 +23,7 @@
   <form action="@url(repository)/wiki/@if(pageName == ""){_new} else {_edit}" method="POST" validate="true">
     <span id="error-pageName" class="error"></span>
     <input type="text" name="pageName" value="@pageName" style="width: 900px; font-weight: bold;" placeholder="Input a page name."/>
-    @helper.html.preview(repository, page.map(_.content).getOrElse(""), true, false, false, "width: 900px; height: 400px;", "")
+    @helper.html.preview(repository, page.map(_.content).getOrElse(""), true, false, "width: 900px; height: 400px;", "")
     <input type="text" name="message" value="" style="width: 900px;" placeholder="Write a small message here explaining this change. (Optional)"/>
     <input type="hidden" name="currentPageName" value="@pageName"/>
     <input type="submit" value="Save" class="btn btn-success">
diff --git a/src/main/twirl/wiki/page.scala.html b/src/main/twirl/wiki/page.scala.html
index 102454d..21a8a62 100644
--- a/src/main/twirl/wiki/page.scala.html
+++ b/src/main/twirl/wiki/page.scala.html
@@ -22,7 +22,7 @@
     </li>
   </ul>
   <div class="markdown-body">
-    @markdown(page.content, repository, true, false, false)
+    @markdown(page.content, repository, true, false)
   </div>
   <div class="small">
     <span class="muted">Last edited by @page.committer at @datetime(page.time)</span>