Nerimity is made by Superkitten, the current solo dev in the project, with quite a few different contributors. I happened to be friends with one of the contributors, so I get it. It is self-hostable to a point (as one of my former acquaintances had tried), though there was some drama over the improper implementation. It is Electron based for the desktop app, and since I have the AppImage, it's Electron shenanigans (TS, JS and others accepted by Electron).
Discussion
Yeah electron is bad.
https://www.linkedin.com/pulse/theres-new-stealer-variant-town-its-using-electron-stay-fully
https://cybermaterial.com/hackers-use-electron-for-infostealer-malware/
https://github.com/jonmest/How-To-Tamper-With-Any-Electron-Application
I use some Electron apps myself, but only if they're local-first like Obsidian. I rarely use Electron anyway.