What is "addventure"

An addventure, also known as a collaborative gamebook, is a type of online interactive fiction that combines aspects of round-robin stories and Choose Your Own Adventure-style tales. Like a round-robin story, an addventure is a form of collaborative fiction in which many authors contribute to a story, each writing discrete segments. However, like a gamebook, the resulting narrative is non-linear, allowing authors to branch out in different directions after each segment of the story. The result is a continually growing work of hypertext fiction.