an ordinary chessplayer wrote yesterday at 01:17:54:

Just to be clear here, since I suspect there was a misunderstanding - I believe John was suggesting lichess here for the actual lichess database, which is the database of all games played on lichess, filterable by rating and time control. This allows you to map out what opening lines and moves are actually popular at your level relative to what a typical reference DB (Megabase, Caissabase, the lichess Masters DB, etc) would say. It varies wildly across rating ranges, and so the latter databases can be a bit misleading. 

I have been working on an open-source, cross-platform alternative to SCID for many months now, I'm calling it Tabiya. In a few months I'm hoping to open it up to beta testers. Anyone reading this that's interested, shoot me a PM and I'll reach back out when the time comes. I have used Chessbase and SCID quite a bit over the years, but find Chessbase to be massively bloated, whilst SCID looks a bit old and can be slightly cumbersome. Tabiya is designed to hopefully be in the sweet spot - looks a bit more modern and does only what I'd consider to be critical and useful for most people trying to improve at chess. It uses Chessground and the color schemes are similar to lichess light/dark mode, so if you like the way lichess looks, you'll probably  like using it. It is already quite far along, and you can do almost everything you'd ever need to, e.g. all the standard databases operations (creating, merging, deleting, backing up, rearranging), analyzing games with engines, accessing opening explorer stats for lichess DBs and a user-chosen reference DB, filtering databases by metadata, positions, position fragments, or what I call "fuzzy" positions (same piece tallies, similar pawn structures). You can spar against the Maia bot at whatever rating is useful to you, and I incorporated an opening book so it plays the exact ratings in the exact proportions for players at that rating. Lastly, you can create puzzle sets yourself or import them from lichess and use the Woodpecker Method, and it automatically tracks all your stats for you so you can see your improvement as you go!

Bare ChessBase + 30 euros to Mark Crowther at TWIC for his complete database back to 1993 + Stockfish 18. Add Leela if your computer has a fast / modern GPU.

Opening study: start in Lichess studies to access their statistics (find moves actually played at your level) and then transfer pgns to Chessbase for long-term storage and access.

Mygames: a database of your games with your notes.