>I used Calibre for a while, and it worked great, once I learned how to avoid its catalogueing parts. Then in 2016 when I switched to Linux, its Linux edition came out a bit heavy and had some quirks, not suitable for the tiny 8" laptop on which I was using it. So I switched to FBReader - lighter, leaner and simpler. The only thing that Calibre has that I wish FBReader had is to rightclick selection and it looks it up in some online dictionary, giving you the brief definition in a tooltip-like window.

Thanks