Define custom fields that can be used across content types, users, comments, terms and other entities. Store the data for these fields in SQL, NoSQL, or use remote storage.
Control exactly what gets shown where on the screen with the new Render API and some truly radical alter hooks. The new RDF module provides semantic web markup.
Administration screens are now far more accessible. Many front-end improvements make it easier for you to build highly accessible websites.
Images and files
Adding images to content is now built in. Generate different versions for thumbnails, previews and other image styles. Private file handling can now be used alongside public files.
Automated code testing
A new automated testing framework with over 30,000 built-in tests allows for continuous integration testing of all Drupal core patches and contributed modules.
Improved database support
A new database layer provides out-of-the-box support for SQLite, MySQL/MariaDB, and PostgreSQL. Install contributed modules to use MS SQL Server, Oracle, and more.
Better distribution support
Use installation profiles to distribute your custom Drupal product. A new API and exportable configurations let you capture more settings in code.
Thanks to a great community effort, over 800 modules are available or under active development for Drupal 7, including Views, Pathauto, and WYSIWYG, with more on the way every day.
To install Drupal 7, you will need:
* Web Server: Apache (recommended), Nginx, Lighttpd, or Microsoft IIS
* Database: MySQL 5.0.15 and higher, PostgreSQL 8.3 and higher, or SQLite 3.x
* PHP: 5.2.4 and higher
* Memory: 32MB (A site with a number of commonly used modules enabled may require 64 MB of memory or more.)
Get it -> Here