Drupal 8
The development to release a stable Drupal 8 version took about four years. The development phased started March 10, 2011. The first beta was released October 1, 2014, right after the new base theme, Classy, got commit to core. A whole new theming layer should make the life of Drupal "themers" easier. On October 7, 2015, the first release candidate was announced. Finally, on November 19, 2015, the first stable version was released.
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