Open Source appeared 25 years ago in the software industry and is now widely used by all digital infrastructures. Companies outside Software industry have recently started showing their interest in this subject; they communicate about their engagement in Open Source and have started exploring Open Source Hardware features. The objectives of this articles are 1) to study why companies in software and other industries, more accustomed to Open Innovation and Open business models, incorporate Open Source as a new product and service development methods and 2) to identify the factors to succeed in such strategic changes. The research is based on expert interviews: 8 Academic Researchers, specialists in the Open Innovation, Open Source, Strategy and/or business Model fields, and 11 Managers, either in software or in industrial companies, practicing Open Innovation or Open Source Strategies. After positioning Open source software and hardware within Open Innovation, the articles identity key objectives and enablers of open source adoption. Key objectives include operational (reduce costs, improve reputation) and strategic (increase the market, dominate or survive on the market) elements. In this category we also identify key tradeoff. To structure key enablers, business model framework is used. Resources include communities as a long-term crowd resource; Competencies include Community management and legal and technical competencies to enable the collaborative work and be accepted by communities; Organization include starting with an Open Innovation process, relying on the community to lead the product development process and modularizing activity; and Value Proposal include hybrid strategies and building useful projects to attract users and communities. Specific issues appear for Open Source Hardware (safety and physical-object issues). We conclude the article with theoretical and managerial contributions and identify research perspectives.