When you use Sitecore Active Directory module it is possible to set up Single Sign On by protecting the file LDAPLogin.aspx with Windows Authentication. Then it is possible to login to Sitecore without entering username and password, when you enter the following URL: http://[yoursite]/sitecore/admin/LDAPLogin.aspx.
This will login the user to the Content Editor or the StartURL entered on the users User Profile in Sitecore.
But what if you want to make it possible for the users to decide for them self, if they would like to login to the Desktop or the Content Editor?
<link rel="stylesheet" href="http://yandex.st/highlightjs/8.0/styles/vs.min.css">
All you have to do now, is to mark up your code snippet in the content with <pre><code>[content]</code</pre> and you are up and running.