This poster aims to facilitate business planning of bootstrapping entrepreneurs who are developing a high-tech business by open-source approach. It draws on scholarly works on business modelling and open-source software to provide a practical tool for entrepreneurs establishing a business by open-source approach. Built on top of established business modelling frameworks, the Open-Source Software Entrepreneurial Business Modelling (OSS_EBM) can be a useful strategic management and entrepreneurial tool. It enables strategists and entrepreneurs to describe, design, challenge, invent, brainstorm, pivot, analyze and improve upon open-source business models.