You'll need a Unix-like system, eg
Linux, to run and compile newsstar. The
curses library (preferably
ncurses) gives extra functionality, but isn't essential. The
gdbm library and headers are needed if newsstar is to
maintain its own history database.
Obviously you'll need the details of at least one news server to download news from. The easiest way to feed articles to most servers is via an rnews batch, but direct injection via NNTP is supported for INN and s-news. The remote server(s) must support the XHDR command. Newsstar used to request articles by their Message-ID, but in 0.11.0 switched to fetching by article number (group index) which should improve performance, especially on poorer servers.
Newsstar optionally uses the NNTP CHECK command to avoid downloading articles the local server already has. If your server/spool doesn't support that, newsstar can maintain its own database of Message-IDs with gdbm. INN supports CHECK, but I don't know in which version it became available; sn and s-news don't, but newsstar can use s-news' database.