[As ever, this is also on the BBC News website]
In the far off past when I was a professional programmer writing software for money I relied on a variety of tools to fix the inevitable errors in my work. These tools would look at my thousands of lines of code and check that I had all my brackets and semi-colons in the right place and that I hadn’t mis-spelled the names of variables or functions.
I also relied on more serious debugging software, programs like ‘dbx’ that could investigate the inner workings of other programs, monitoring them as they ran and giving me complete access to the instructions I was executing and the data structures they were manipulating.