Neorg
Modernity meets insane extensibility
...Not only does this yield a low barrier for entry for new users it also ensures that all features are integrated with each other and speak the same underlying language. The file format is built to be expressive and easy to parse, which also makes .norg files easily usable anywhere outside of Neorg itself. A good way of thinking about Neorg is as a plaintext environment that can be adapted to a variety of use cases. If a problem can be represented using raw text, it can be solved using Neorg.