I was fooling around with the second alpha release of the Bootstrap theme for Drupal8. I hit a snag, made a wish (by posting an issue to drupal.org) and Lo! and Behold! Not long after the wish was granted and a Beta was released.
If you're one of those people who uses Drupal to publish stuff online, and just want to get something up quickly without using Drupal's default Bartik theme, then you might want to take a look at Bootstrap.