The authors of the CPO programs.
The original author of the earliest electron optics computer programs at the University of Manchester, UK, was Frank Read, who was the leader of the Atomic and Molecular Group (which would now be called the Quantum Physics Group). Frank was an experimental physicist who used electron beams to fire at atoms and molecules. He needed good data on electrostatic lenses to focus the electrons but discovered that the only available data in the literature was of poor quality because about half the time the principal planes did not cross, as they must do according to theory. He therefore wrote an FDM program, which he could could not get to converge satisfactorily for the aperture lenses that he was using (this is now known to be because the FDM has difficulties in simulating the singular fields near sharp apertures). He therefore took a leaf from nature and realised that the fields are generated by the surface charges on the electrodes, and so wrote a 'charge density' program, now known to be a version of the BEM. This worked well and formed the basis of all the later work on lens properties. His main field was always experimental quantum physics, but he developed the early MAN-2D programs, with students, and is a co-author of the book Electrostatic lenses, by E Harting and F H Read, Elsevier Publishing Company, Amsterdam (1976). He was later joined, see history of the company, by Nick Bowring who was a computer expert who had experience in interfacing programs to make them accessible to the general user. He resigned from CPO Ltd in 2014. Frank retired from physics in 2002 and since then has worked as an independent consultant engineer in charged particle optics. He has more than 60 refereed papers on charged particle optics and instrumentation (one of them cited more than 500 times) and more than 150 on physics (about 10 of which have been cited more than 100 times).
Frank was joined in 2015 by Ryan O'Neill, who has redesigned the web pages and much else and has put new life into the venture.