Started in 2007 by John and Hank Green as a way to communicate whit each other for the year.
Originally called Brotherhood 2.0 it ran from January 1 to December 31. In the series John and Hank went without text based communication with each other for the year. On alternate days John or Hank posted a vlog for the other on the YouTube channel. After the project was over the Green Brothers extended the project indefinitely.