This is necessary if you are viewing a particular website you love the layout and the theme but could't find out the particle cms the owner used in designing them 'cos they might remove those credit link as part of their choice design.
you can use this short cut
to display the source code from there try finding script and css directory you might as well look for the name of the theme they are using and make a search for it on google.
this is a second trick that works magic I found it in a friend's wall long time ago
Try identifying the actual location the site is using the CMS. Often site owners don’t use the CMS in Root (/) directory of the site. e.g. for blogs, they may use another /blog/ folder or virtuemart users may use /store/ folder.
Follow these specific guidelines for identifying CMS of an website:
Identify WordPress Sites
How would you know if the site uses WordPress. Simple, go to location that looks like these:http://www.example.com/wp-admin
Alternatively, you can see the link like this use these links:http://www.example.com/wp-login.php
If you see a login page asking for User ID and Password, then the site/blog or the blog portion of the site is build with WordPress.
Identify Joomla Sites
The default location for Joomla admin panel looks like this:http://www.example.com/administratorhttp://www.example.com/store/administrator
These administrator pages are publicly accessible. So if you can see them, then the site is using Joomla. If Joomla is used as CMS of the site, then you can access them even if you use Search Engine Friendly (SEF) URLs.
But, the problem is, now a days many CMSes use the /administrator/ URL after the domain as their Admin Panel Login page. But, as you go to that page, you might see the Joomla logo on the Admin Panel login page, unless the webmaster changes it.
Identify Drupal Sites
Drupal Dashboard is located usually in:http://www.example.com/?q=user
But, things can change if you are using Search Engine Friendly URLs in Drupal using Mod_Rewrite. The usual location for the Drupal Dashboard, when the SEF URL is used, is:http://www.example.com/user
If you can see the login page, you have your CMS. But, this can be tricky. Please read through to know why.
Identify Magento Ecommerce Site
Magento sites also use http://www.example.com/admin
URL as the default admin panel log in page. But, there is a patten. The template you use in Magento is called skin. So, if you see location of the resources in the HTML code of the site starts with: http://www.example.com/skin/frontend/,
then it is a Magento Site.