The WordPress O2 plugin with P2-Breathe theme results in a Facebook-like or Twitter-like streaming interface. The idea was first presented in 2013, evolving from the P2 theme in 2009 (originally launched as Prologue in 2008) when hosted on wordpress.com.
“Beau Lebens: Taking WordPress to the Front End with O2” | Wordcamp San Francisco 2013 at https://wordpress.tv/2013/08/08/beau-lebens-taking-wordpress-to-the-front-end-with-o2/ .
In 2015, o2 became available as a open source plugin installable on self-hosted WordPress blogs. See “o2 is Now Available on Github | Sarah Gooding | June 15, 2015 | WP Tavern at https://wptavern.com/o2-is-now-available-on-github .
O2 is a refinement of a communications tool used internally by Automattic. See “How P2 Changed Automattic” | Matt Mullenweg | May 5, 2009 at https://ma.tt/2009/05/how-p2-changed-automattic/ .
The central site for O2 is at https://geto2.com/ .