Open source describes practices in production and development that promote access to the end product's source materials, spreading development burden amongst individuals and companies. This model has resulted in a large and efficient ecosystem and unheralded software innovation, freely available to society. Open source methods are also increasingly being applied in other fields of endeavour, such as biotechnology or cultural production. But under financial reporting framework, general volunteer activity is not reflected on financial statements. As a result, there is not value of volunteer contributions and there is also no single source for cost estimates of how much it has taken to develop an open source technology. This volunteer activity encloses not only individuals but corporations developing and contributing open source products. Standard methodology for reporting open source asset valuation is needed and must include value creation from the perspective of the different stakeholders.