In late 2021, midway through the COVID-19 pandemic, George Stagg was preparing to give exams to his mathematics and statistics students at the University of Newcastle, UK. Some would use laptops, others would opt for tablets or mobile phones. Not all of them could even use the programming language that was the subject of the test: the statistical language R. “We had no control, really, over what devices those students were using,” says Stagg.Stagg and his colleagues set up a server so that stude...