The low-power Internet of Things (IoT) has been thriving because of the recent technological advancement and ecosystems meeting the vertical application requirements and market needs. An open IoT technology ecosystem of the low-power IoT has become increasingly important to all the players and stakeholders and to the research community. However, there are several mainstream low-power IoT ecosystems available out of industry consortia or research projects and there are different models implied in them. We need to identify the working framework behind the scene and find out the principle of driving the future trends in the industry and research community. With a close look at these IoT technology ecosystems, four major business models are identified that can lead to the proposed ecosystem framework. The framework considers the technical building blocks, market needs, and business vertical segments, where these parts are making the IoT evolve as a whole for the years to come.