OBS Studio
OBS Studio is a free and open-source software suite for recording and live streaming. Written in C, C++ and Qt, OBS provides real-time source and device capture, scene composition, encoding, recording, and broadcasting. Transmission of data is primarily done via the Real Time Messaging Protocol (RTMP) and can be sent to any RTMP supporting destination, including many presets for streaming websites such as YouTube, Twitch, Instagram and Facebook.