CERN-HSF (High-Energy Physics Software Foundation) is the umbrella organization for high-energy physics-related projects in GSoC. The HEP Software Foundation (http://hepsoftwarefoundation.org/) facilitates the coordination of common international efforts in high-energy physics software and computing. CERN (European Organization for Nuclear Research, https://home.cern) has participated in GSoC since 2011 as the CERN-SFT group, which provides common software for CERN's experiments. In 2017, the program expanded to include many software projects from the whole field of high-energy physics. The vast majority of our GSoC projects do not require any physics knowledge. The experiments at CERN, such as the Large Hadron Collider, the world’s largest and most powerful particle accelerator (http://home.cern/topics/large-hadron-collider) try to answer fundamental questions about the Universe. For example, what is the nature of mass? What are the elementary building blocks of the Universe? What was the early Universe like? What is the nature of dark matter and dark energy? Why is there an asymmetry between matter and antimatter? In 2012, LHC experiments announced the discovery of a new particle, the Higgs Boson, that helps explain how particles obtain mass. Also, CERN is the birthplace of the World Wide Web. Today, particle physicists are working on analyzing the data from the experiments to study the properties of the newly discovered particle and to search for new physics, such as dark matter or extra dimensions. This requires a lot of sophisticated software. The open-source high-energy physics projects to which students can contribute during GSoC span many high-energy physics software projects: data analysis, detector and accelerator simulation, event reconstruction, data management and many others. We look forward to your contributions!