Toxic is a client with an ncurses interface, written entirely in C. It has support for all basic features, as well as 1-on-1 audio/video chats, and is capable of working on bare-bones systems that lack graphical interfaces.

uTox is described as 'µTox is the lightweight client with minimal dependencies; it not only looks pretty, it runs fast! µTox is available for Windows, OS X, and Linux (Android support is experimental), with full support for chat, file transfers, audio/video calling, and desktop sharing' and is a instant messenger in the social & communications category. There are more than 25 alternatives to uTox for a variety of platforms, including Linux, Windows, Android, Mac and iPhone apps. The best uTox alternative is Signal, which is both free and Open Source. Other great apps like uTox are Tox, Molly, FluffyChat and Status.
Toxic is a client with an ncurses interface, written entirely in C. It has support for all basic features, as well as 1-on-1 audio/video chats, and is capable of working on bare-bones systems that lack graphical interfaces.

Ricin aims to be a secure, lightweight, hackable and fully-customizable Tox client with focus on user experience. Development is lead by SkyzohKey.
