The parts about no complicated file formats, ease of backup, keyboard only, fast, easy to use, text only, etc. strike close to home for me because this is what

The parts about no complicated file formats, ease of backup, keyboard only, fast, easy to use, text only, etc. strike close to home for me because this is what I also desired, to the point that I've written my own program to keep various notes. It also had to be portable (Windows and Linux) because at the time I had another weaker laptop that had to run Fedora and I wanted to use it there too. I just couldn't find such a program, everything was bad, not portable or 'rich' (aka images, styles, etc. aka needs mouse or has a complex file format).