Abstract Teaching C ++ programming to noncomputer science majors comes with the burden of setting up an integrated development environment, a struggle for most students. Therefore, we present the open source tool, C ++ Explorer, a JupyterHub deployment for interactively developing C ++ code. Students can connect to the server without installing anything, and, almost instantly, they can begin to engage with code using the notebooks. Another aspect of code development is remote communication with coworkers or the community. To develop this skill, we use GitHub classroom to provide feedback on the assignments and practice remote communication. C ++ Explorer was used in the fall of 2019 and 2020 to teach parallel computation to mathematics students. At the end of the class, we gather students' feedback. This data will be used to continue improving the course. In addition, we present a Telegram ® bot for the communication with the server using smart phones or tablets. However, this tool was not used in the course and will be explored in future teaching.

Octo-Tiger is a code for modeling three-dimensional self-gravitating astrophysical fluids. It was particularly designed for the study of dynamical mass transfer between interacting binary stars. Octo-Tiger is parallelized for distributed systems using the asynchronous many-task runtime system, the C++ standard library for parallelism and concurrency (HPX) and utilizes CUDA for its gravity solver. Recently, we have remodeled Octo-Tiger’s hydro solver to use a three-dimensional reconstruction scheme. In addition, we have ported the hydro solver to GPU using CUDA kernels. We present scaling results for the new hydro kernels on ORNL’s Summit machine using a Sedov-Taylor blast wave problem. We also compare Octo-Tiger’s new hydro scheme with its old hydro scheme, using a rotating star as a test problem.

We study the simulation of stellar mergers, which requires complex simulations with high computational demands. We have developed Octo-Tiger, a finite volume grid-based hydrodynamics simulation code with Adaptive Mesh Refinement which is unique in conserving both linear and angular momentum to machine precision. To face the challenge of increasingly complex, diverse, and heterogeneous HPC systems, Octo-Tiger relies on high-level programming abstractions.