The goal of the BioASQ project is to push the research frontier towards hybrid information systems. We aim to promote systems and approaches that are able to deal with the whole diversity of the Web, especially for, but not restricted to the context of bio-medicine. This goal is pursued by the organization of challenges. The first challenge consisted of two tasks: semantic indexing and question answering. 157 systems were registered by 12 different participants for the semantic indexing task, of which between 19 and 29 participated in each batch. The question answering task was tackled by 15 systems, which were developed by three different organizations. Between 2 and 5 of these systems addressed each batch. Overall, the best systems were able to outperform the strong baselines provided in the experiments in two out of three settings. This suggests that advances over the state of the art were achieved through the BioASQ challenge but also that the benchmark in itself is very challenging. In this paper, we present the data used during the challenge as well as the technologies which were at the core of the participants' frameworks.