In the past years I have used much
Keynote NF, the evolution of Keynote. Now I would need something comparable on Linux. Gnote, but the files are stored in a fixed place. I would need a text database file that can be saved and loaded anywhere, as I separate databases on purpose. I have checked emacs Org-mode. Nice. But far from what I expected. Actually, any code folding app in theory sounds pretty much the same, yet the feel is not the same. RedNotebook. Nice. I have used it before. But it's a diary. Notecase has ceased to exist and has been replaced by a paid Notecase Pro.
It should be text only and fast. I use only text and extra features might slow it down. But that is not a restriction. Markdown support would be a nice feature.
I need something that is packed for Fedora x64.