PBLang is a versatile flat file BBS, requiring only PHP 4.02 support. It has a wide range of user specific settings, various skins/layouts, configurable forums, moderators, email notifications, several levels of restrictions, membership groups, a completely configurable layout, sortable members list, avatars, etc. The emphasis is on configurability and reliability.
VuohiMatik is a BBS software designed with large BBS systems in mind. It has filearea operations which work well on tens of thousands of files online, giving the end-user a uniform interface to perform quick selections and searches on the fileareas using various search conditions. Otherwise, it provides similar capabilities to AmiExpress and DayDream.
Chindi is a file transfer server/client package written in Java with functionality similar to that of an FTP server. The goal is to create an old-school BBS-system combined with a FTP server. All transfers are encrypted using a fast stream cipher combined with RSA encryption for the transfer of the keys.
Volley is a modular client/server application for chat, file sharing, and so forth. It is similar to Hotline, except its modular design allows for the addition of more services than just the usual chat, files, and news; there could be multiplayer games, and online meeting tools such as virtual whiteboards.