+* lynx (for converting HTML messages to text)
+* Perl and several modules: (Debian package name)
+ - Date::Parse libtimedate-perl
+ - Email::Filter libemail-filter-perl
+ - Email::MIME libemail-mime-perl
+ - Email::MIME::ContentType libemail-mime-contenttype-perl
+ - Encode::MIME::Header perl
+ - File::Path::Expand libfile-path-expand-perl
+ - IPC::Run libipc-run-perl
+
+Optional modules:
+
+ - Plack[1] libplack-perl
+ - Mail::Thread (2.5+)[1] libmail-thread-perl
+ - URI::Escape[1] liburi-perl
+ - Search::Xapian[3] libsearch-xapian-perl
+ - IO::Compress::Gzip[3] libio-compress-perl
+ - DBI[3] libdbi-perl
+ - DBD::SQLite[3] libdbd-sqlite3-perl
+ - Danga::Socket[4] libdanga-socket-perl
+ - Net::Server[4] libnet-server-perl
+
+[1] - Only required for serving/generating Atom and HTML pages.
+[3] - Optional for HTML web interface and HTTP/NNTP servers
+[4] - Optional for HTTP and NNTP servers