One historical side note about rn(1): that was the news reader program we modified into an
NNTP client for the first NNTP software distribution in 1986 for two reasons: filters
(KILL files), and it engaged in prefetching the next article to be read which we thought
would be especially important for an NNTP client experiencing network latency to fetch an
article for a reader - we wanted to try and preserve a snappy user interface for netnews.
Erik Fair