SoundBetter - Marketplace for musicians and music production professionals
Jenkins - Jenkins is an open-source continuous integration server with 300+ plugins to support all kinds of software development
Melody ML - Easily separate audio tracks using machine learning
CircleCI - CircleCI gives web developers powerful Continuous Integration and Deployment with easy setup and maintenance.
PrimoMusic - An iTunes alternative made to manage iPhone/iPod media files
Travis CI - Focus on writing code. Let Travis CI take care of running your tests and deploying your apps.