Magiterm is an SDL2 based SSH / Telnet client for Bulletin Board Systems. It supports basic ANSI, extended pallets (8 bit and 24 bit), font loading and font switching, sixel, ZModem and more.
Magiterm is available as a Win32 installer, packages for linux and source code for other OSes, it is known to compile on Windows 10, Linux, FreeBSD, NetBSD, Haiku and macOS.
TitanMail is a QT based QWK offline mail reader. It is available as a win32 installer and source code for other operating systems.
Gophari is a wxWidgets based Gopher client. It is available for win32 as an installer and source code for other operating systems.