OBS: Open Broadcaster Software Studio (formerly known as OBS Multiplatform) is free and open source software for live streaming and video recording.
- Live streaming to Twitch, YouTube, GoodGame, DailyMotion, Hitbox and any other RTMP server.
- Record your game, screen, webcam or any other source to MP4 or FLV.
- Encoding using H.264 (x264) and AAC for streams and recordings.
- Support for Intel Quick Sync Video (QSV) and NVIDIA NVENC.
- GPU-based game capture for high performance game streaming.
- Unlimited number of scenes and sources.
- DirectShow capture device support (webcams, capture cards, etc).
…and many other features. For free. At all. 😉
OBS Studio developed with cross-platform support. Official releases are currently available for Windows, Mac and Ubuntu Linux. There are also some unofficial releases for Arch Linux, OpenSUSE and Gentoo. And of course, since source code is open, you can build OBS for your OS.