These days there are plenty of file-based digital garden tools. But many of them treat the document system and the UI as one bundle, which always bothered me. I mostly write in NeoVim, so I wanted the document system itself, the editing environment, and the application (usually a static site) to be separate things. I didn't need an all-in-one. I needed a system where I could fine-tune the rules programmatically, and since sharing my digital garden with others matters too, the application UI had to be customizable as well. So I created Simpesys.
Simpesys focuses only on the document system, things like hierarchy and cross-references between documents, and keeps the user interface as a completely separate layer. The document system is the trickiest part of building a digital garden, and Simpesys provides that as a headless tool. The UI is handled through a plugin system, so users can customize it however they want. The users could even use another tool's UI on top of Simpesys if they wanted. (Respecting the original authors and their licenses, of course.)
It's not perfect yet, but I hope it inspires anyone with similar needs. As the first user of Simpesys, I keep improving it.
Simpesys's homepage is itself built with Simpesys: https://pedia.simpesys.deno.net/