Drupal is content management system that is flexible and packed full of features. It is open source software that is free for you to use and modify.
Over the last couple of years or so, Drupal has become the platform to run websites that require a lot of community and content management features. Its range includes simple brochure sites and personal blogs, to full-featured social networking sites, news sites, portals and e-commerce websites. It allows users to easily publish, manage & organize a wide variety of content on a website.
Drupal has proven to be the most robust platform available in the content management system market. The number of features available through modules is always growing - at a very fast pace.

Some features include:

• Blogs
• Forums
• Polls
• Voting & Reviews
• Threaded comments
• Multiple Users
• User Logins
• User access permissions
• Friendly URLs
• Moderated submit links
• Templating
• Newsletter subscriptions & sending
• Shopping cart features – inventory, features, integration with Paypal
• Metatags/keywords, descriptions
• Send to friend
• Advanced search
• Google Analytics
• Newsfeeds
• RSS
• News aggregator
• Taxonomy –grouping by categories
• Sites maps
• Link submissions
• Captcha Feature
• Web forms
• Calendar
• Google Maps integration
• Formatting
• Logging and Reporting
• File uploads & downloads
• Audios and Videos playing

Wait!! There are more features than we can list here. Want to know them? Get them @ http://drupal.org/features

Some Remarkable Drupal Powered Websites

• Sun Learning Exchange : Sun Microsystems recently launched another cool Drupal site - Sun Learning Exchange. The site enables Sun employees to easily publish rich media training content such as videos, podcasts, and documents to be accessed by all Sun employees and customers.
• Battlefield Heroes : Computer and video game developer Electronic Arts (EA) is using Drupal for their upcoming shooter game called Battlefield Heroes. According to the trailer, they have big plans for their website. They want to use it to host a long-running territorial conflict meta-game. Curious to learn if that will be built in Drupal too.
• Warner Bros Records : The main Warner Bros Records website, http://www.warnerbrosrecords.com (or http://wbr.com), is a Drupal site. Well, it looks smashing! People like Madonna, Metallica, Paris Hilton and the White Stripes work for Warner Bros Records, we can expect more coolrupal sites.
• Mission Metallica : Yes thats true !! Metallica's new album is coming out in September 2008. For this wonderful occasion, Warner launched a sneak-preview site on May, 12th: Mission Metallica. I already subscribed to the newsletter back then but now that they opened for registration, I noticed that they are using Drupal!
• Adobe using Drupal for flex.org : Adobe just relaunched flex.org as a Drupal site. The backend of the Flex powered showcase site, http://flex.org/showcase, is also using Drupal: it communicates with the Flex front-end using the Services and the AMFPHP modules.
• Jabber using Drupal : This is really cool. For starters, An open, secure technology for instant messaging and a whole lot more. It is A decentralized network of IM services in which your messages are not monitored by a big company like AOL, Microsoft, or Yahoo. You can even run your own server! So its nice to see Drupal talking with Jabber.
• Femina - Women's Magazine : Drupal continues to rock the newspaper and magazine world. Femina, a women's magazine, recently switched to Drupal. Femina is owned by Edipresse, one of Europe's biggest media and communications companies. They publish more than 200 titles, including some leading European newspapers
• Website for Belgian Prime Minister : When a new Belgian government was sworn in, ending a political deadlock of nine months, they started to develop a website for their premiere. With the new government comes a new Prime Minister, and with the new Prime Minister came a new website. But at least the Prime Minister's official website is using Drupal.
• Deputy PM too! : After Belgian Prime Minister Yves Leterme, Deputy Prime Minister Joëlle Milquet also started using Drupal. Check it out at http://milquet.belgium.be. More information in this IT Professionals article (Dutch).
• AOL Corporate : Its is well known that AOL was using Drupal for their AOL Developer Network at http://dev.aol.com. Turns out that AOL also started using Drupal for their corporate information website at http://corp.aol.com. Is AOL falling in love with Drupal?
• Britney Spears falls in love with Drupal : Britney Spears' official website just relaunched using Drupal. Check it out at http://britney.com. The site was built by her record label, Sony BMG. Oops! We did it again!
• Amnesty International : Amnesty International was relaunched on Drupal. It looks like Drupal's localization (l10n) and internationalization (i18n) features were used to translate the website into 3 languages; an Arabic translation is available as well. (Arabic is written predominantly right-to-left which, frankly, is funny to watch but hard to implement in a CMS.)
• Many universities use Drupal: More and more universities start to embrace Drupal by moving departmental sites to Drupal. It is an emerging trend, and one that bodes well for Drupal. A lot of students are being introduced to Drupal this way. These are important signs that Drupal is gaining momentum in the enterprise.

Paul Albert of Cornell University shared a great presentation that compares Drupal to Fatwire (a proprietary, enterprise WCMS), and that provides an excellent overview of how other universities are using Drupal. If you want to bring Drupal into your enterprise, you should watch the video of Paul's presentation below.

Just like the features of Drupal, there are lots of Drupal sites which should be mentioned but could not be mentioned here. But the conclusion is Drupal is way to go !!!