Drupal Distributions

Dries Buytaert (Creator of Drupal) announces the Spark Distribution ready for alpha testing. Spark distribution is a Drupal 7 distribution which aims to prototype cutting-edge authoring experience improvements for inclusion in Drupal 8 core.

What are Distributions?

Distributions are a collection of pre-configured themes and modules for feature-rich web sites giving you a head start on building your site.Also know as "pre-configured" versions of Drupal. Distributions are full copies of Drupal that include Drupal Core, along with additional software such as themes, modules, libraries, and installation profiles.Drupal Distributions started from Drupal 5.0 to allow people to create ready-made downloadable packages with their own focus and vision. This is to enable Drupal to reach out to both new and different markets.
Drupal distributions are categorized into two main types:
Full-featured Distributions: With this type, you can quickly and easily set up a site for a specialized purpose such as academic, business, government, nonprofit, publishing, social, etc.
Other distributions:This type is more suited for developers and site builders.e.gs of such distributions are (Acquia Drupal, Build Kit, Cocomore Drupal, Commerce Kickstart, etc)
Some examples of popular distributions are :
Spark (a Drupal distribution which aims to be "the Pressflow of Drupal authoring experience.")
OpenAtrium (an intranet distribution)
Acquia Drupal (a convenience distribution for site builders)
OpenPublish (a distribution for online publishers)
Pressflow (a distribution with performance and scalability improvements)

Finding distributions

Drupal distributions are listed as projects in Download & Extend similar to that of modules and themes.These distributions can be filterable by compatibility, popularity, keyword, and more.Some distributions include code (such as the jQuery library) that cannot be hosted on drupal.org due to incompatible licensing, so downloads of these distributions are provided via a 3rd party website.

Installing a Drupal Distribution

Installing a drupal distribution is just as installing drupal.The only thing is that, in the process of installing a drupal distribution you will need to select/choose which installation profile you want.Installation profiles are what a developer creates as the basis of distributions. An installation profile is a script that only runs once during your Drupal site install.They define installation steps (such as enabling modules, defining content types, etc.) that run after Drupal's base installation when you first install Drupal.
They make it possible to quickly set up a complex, use-specific site in fewer steps than if installing and configuring elements individually.Some distributions have specific installation instructions which are normally documented by the developer.
For more information visit http://drupal.org/node/1085382
So now,you can consider to look into Drupal distributions just like the way you look out for modules and themes to see if a distribution will suit your project.For-instance,if you're planning to build a news site,you can take a look at OpenPublish and see if it meets most of your features you intend to implement.I can guarantee you that,most of these distributions will meet at about close to 40% - 60% of your needs and probably even adopt some of their custom developed modules or features.