Scid exists of course, I've used it since forever and it works fine. But you have to find your own games to fill it with (probably from The Week In Chess) and i

Scid exists of course, I've used it since forever and it works fine. But you have to find your own games to fill it with (probably from The Week In Chess) and it looks like Linux did in 1998. Most of my opening stuff is just in a bunch of Lichess studies these days though.