Mixxx 2.0 recently released, is the most advanced, free, open source DJ software designed for DJs that allows you to mix songs live. Mixxx natively supports MP3, OGG, FLAC, WAVE, and AIFF playback (with plugins to support additional formats) and can be controlled by numerous DJ MIDI controllers. Turntables with timecoded vinyl can also be used to control Mixxx through the vinyl control feature. Mixxx runs on the Linux, Mac OS X and Windows operating systems.
Open Broadcaster Studio 0.12.3 recently released, is a complete rewrite of the original OBS from the ground up, with the main goals of course being multiplatform support, a more thorough feature set, and a much more powerful API. Open Broadcaster Software is a free and open source software for video recording and live streaming. Supported features include: Encoding using H264 (x264) and AAC. Support for Intel Quick Sync Video (QSV) and NVENC.
Microsoft had just announced during the Connect(); 2015 developer event on November 18, 2015, that its Visual Studio Code Integrated Development Environment software is now open source. The Visual Studio code which is a web-focused IDE based on Atom, and not the full-blown Visual Studio IDE is now available on GitHub. The cross-platform web and cloud development code editor (IDE) now distributed for free as an open-source application, is licensed under the MIT license for all supported operating systems, including GNU/Linux, Mac OS X, and, of course, Microsoft Windows.