Everyone knows that astronomy can be an expensive hobby! For this reason a great tradition has arisen among amateur astronomers of designing and building things for themselves where possible. I am no exception to this tradition, though in my case it is mostly about writing software (since that's what I spent most of my career doing). Most of the stuff I wrote in my career was made freely available in the academic world, so I am hard-wired into the idea of free software. I am therefore happy to make the software listed below available to anyone who can use it - on the understanding that the copyright will be respected, it can never be passed on for money and that it comes with absolutely no warranties.