Technological resources have been an important source of innovation in companies. They play a key role in the development of new products and services. However, the upfront investment in technical resources to enable the development of these new products and services can be quite high. Therefore, managers ask for well elaborated business cases before making investments. These business cases rely on market research to back up their assumptions rather than in-market testing. We argue that the advent of open source software (OSS) creates an opportunity space for companies to build low-cost prototypes and test their ideas in the market. Little is known about how OSS plays a role in allowing these firms to enhance product development. Using qualitative case studies, the paper sheds light on how OSS acts as a bricolage mechanism for technological innovation in the ICT services industry.