Neverending Story BBS was a piece of software for a few different 8-bit microcomputers (in fact, they were completely different codebases) like the Commodore 64 and Apple II. On the Commodore 64 version, there was no real downloads or message base other than an ongoing story that was written by the users. A user would log in, read the story so far, and if they desired, contribute to the continuation of the story. The requirements for running it were small, requiring only a modem, some kind of disk drive (a Commodore 1541 would do), and a telephone line.
Later on, a similar program was created that was a door for MS-DOS based BBSes, including a chain for early versions of WWIV and for Major BBS.