The sn NNTP Server

What it is

sn is a small news system for small sites serving perhaps a few dozen newsgroups, and with a slow connection to the internet. It is similar to Leafnode. The target user is a home or SOHO with a single modem connection to the Internet, maybe running IP masq or similar, and serving a few workstations.

sn is different

sn is fast. The news fetcher implements command pipelining and parallel fetches, so high modem latency doesn't cost you. (You can also throttle sn down, if it's too fast).

sn is flexible. You can subscribe to newsgroups on several upstream sites, and you can create local newsgroups that are not propagated upstream. sn can make mailing lists look like newsgroups transparently.

sn is non-intrusive. It has no configuration files, only control files with simple semantics, so it's suited to being run in an automated fashion.

sn is small. It batches 10 (default) articles per file, so conserving inodes and reducing disk block fragments. sn can also compress the article bodies. It aliases cross posts rather than making separate copies. It does not maintain a bulky overview database; instead it gets overview information directly from the articles. Spool metadata is 5% to 10% of the total spool size, even with compression. You don't need to build a separate file system just to spool news.

sn doesn't have to be set up for the system. You can use it privately, and your users can maintain their own news spool without building sn.

sn has limitations

Because the news spool is in an unconventional format, news readers can read news locally only via NNTP.

IHAVE is not supported. Use POST instead.

sn has no idea of distributions.

sn can't handle thousands of newsgroups. A hundred is comfortable.

The method sn uses to alias cross posts is similar to filesystem symlinks rather than hard links, in that if the original article is expired, the alias breaks.

sn doesn't know how to filter spam.

Newsgroup names are subject to the same length limitations as any filename.


sn is beta. It should work on most UNIXish systems, as long as the GNU tools are installed. (Tested on Linux (main development platform), Solaris and FreeBSD.) If it runs on your machine, let me know. Or if it doesn't run.

You need zlib if you decide to compile in the compression feature.

You'll need inetd or tcpserver to run the daemon. If you use inetd you will probably also want tcpd (tcp wrappers).

I am interested in bug reports, comments, and suggestions.

Mailing list

There used to be a mailing list available.

The mailing list is archived at, see the newsgroup.


Distribution of sn is covered by the GNU GPL. See file COPYING. Use of sn is not restricted. No express or implied warranty of fitness for any purpose (but I'm still interested in bug reports and comments).


sn was created by Harold Tay and maintained by him until version 0.3.2.
From 0.3.3 onwards, sn is maintained by Patrik Rådman ( For details see the CHANGES file.


You can download sn from this web site or from ibiblio.

External links

Links to sites elsewhere on the web.