bnews-utils is a series of programs that allow you to download, upload, decode and/or encode "Bommanews"-encoded files on an NNTP-like network. For more technical information about this encoding, visit the bnews site.
It also features a standalone ydec decoder. You can find more information about yenc here. If you are interested in an yenc-poster/encoder, have a look at yencee by Thore Harald Hoye. Pan now includes support for ydecoding articles, so if you are a *n*x user, you may want to check out the 0.11.3 and 0.12 (or later) releases.
Warning: pan 0.12.x seems to be unable to download bommanews files. I would suggest you keep using the 0.11.X releases or switch to "bnews-fetch.pl" which is included with the distribution. It is rumoured that 0.11.94 also has problems. (not verified)
bnews-utils is known to compile and run on: Linux/ia32, Linux/alpha, Solaris, MacOS X, cygwin, ...