The emergence of computer networks and electronic communication made the writing of collaborative fiction faster and more convenient than previous forms of correspondence. Round-robin stories were being written on bulletin board systems, mailing lists and USENET news groups, and many variations of the format were tried. One early form of branching story that emerged, where participants of such a round-robin group would start telling side-stories in parallel with the main story as it was still being created, led to very confusing and hard-to-follow stories if multiple branches were concurrently being extended on the same board or mailing list. Soon systems emerged in which such branches were formalized and easily separated from the main story.