There are a couple I have in mind. Like many techies, I am a huge fan of RSS for content distribution and XMPP for federated communication.
The really niche one I like is S-expressions as a data format and configuration in place of json, yaml, toml, etc.
I am a big fan of Plaintext formats, although I wish markdown had a few more features like tables.
I do recommend emacs though. It is not the greatest editor, but it is an amazing experience. It is such an amazing experiment, that has an extensive set of different ways of looking at content and code - it will change how you think about coding.