ChessX is free chess database software to manage, view and annotate chess games. It's written in Qt 4, but is being prepared for Qt 5 (I had a little contribution in that as I made it to compile with Qt 5. It wasn't much work.). It is quite functional right now, but best is to try it for yourself.

Earlier I reported there wasn't anyone to develop it, but now situation is much better as commits are quite systematic and there're people on the mailing list wanting to work on ChessX, but there never is enough developers so please check the source code, get to know it and contribute. If you're into chess it'll be for your own benefit as well.