VLC Media Player - VLC is a free and open source cross-platform multimedia player and framework.
Jenkins - Jenkins is an open-source continuous integration server with 300+ plugins to support all kinds of software development
AIMP - AIMP : Free Audio Player : Официальный сайт программы
CircleCI - CircleCI gives web developers powerful Continuous Integration and Deployment with easy setup and maintenance.
foobar2000 - An advanced freeware audio player for the Windows platform.
Travis CI - Focus on writing code. Let Travis CI take care of running your tests and deploying your apps.