Zets
This is a notes repository that acts as a general collection. The subjects of each note are broken into a "card" like structure loosely based on the Zettlekasten method.
I find that I also need a repository for structured notes that extend past the arbitrary length limit for memory management, so this is intermingled with general purpose long-form notes.
The tool I use to create these is zet-cli, which is geared toward Linux users.