I am a retired software engineer. That work was initially on the Space Shuttle Backup Flight System software. I then moved on to embedded avionics equipment in commercial aircraft, both the large air transport and smaller general aviation aircraft. This included requirements analysis, SW design & development, and formal testing to meet FAA requirements. I also spent considerable time in tool development, for the requirements specification and analysis including a formal requirements language, for the software design & development including auto-coders and for testing with auto-test generation. I also developed software at home and used the Microsoft office products: Excel, Word, and Access, with their macro capabilities. For most of my career I was a Perl enthusiast, but having come upon python, I've been converted. Over my career, I have worked on mainframes down to PCs, and have worked under most of the OS's that are out there.